tag:blogger.com,1999:blog-55260576060071052402024-03-19T04:21:09.513-04:0070 MICROWAVE CIRCUIT DESIGN - conocimientos.com.veMICROWAVE CIRCUIT DESIGN. Smith Chart, Network Parameters, Two Ports. Rectangular waveguides, Microstrip Transmission Lines. Smith Chart. Impedance Matching. S-Parameters, Properties of S-Parameters S-Parameter. Passive Components, Signal Flow Graphs, Amplifier (SSA) Design. Small Signal Amplifier (SSA) Design. Low Noise Amplifier DesignTecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.comBlogger47125tag:blogger.com,1999:blog-5526057606007105240.post-36878948635085018512011-06-21T19:52:00.002-04:302011-06-21T19:52:54.786-04:30Carta de Smith Problema 4<iframe class="scribd_iframe_embed" data-aspect-ratio="" data-auto-height="true" frameborder="0" height="600" id="doc_61370" scrolling="no" src="http://www.scribd.com/embeds/58425929/content?start_page=1&view_mode=list&access_key=key-s33hkm3t5zjcoso7860" width="100%"></iframe>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-65668496331950549042011-06-21T19:47:00.001-04:302011-06-21T19:47:48.829-04:30Carta de Smith Problema 3<iframe class="scribd_iframe_embed" data-aspect-ratio="0.772727272727273" data-auto-height="true" frameborder="0" height="600" id="doc_97131" scrolling="no" src="http://www.scribd.com/embeds/58425588/content?start_page=1&view_mode=list&access_key=key-298xuyjhpwhmbpe09m9k" width="100%"></iframe><script type="text/javascript">
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</script>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-70895225637726830902010-07-17T22:04:00.002-04:302010-07-25T08:43:28.503-04:30Monolithic VCO tackles triple bands<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Trimming the single-chip PLL + VCO solution introduced last spring, National Semiconductor Corp<b>.</b> has developed a new family of monolithic RF voltage-controlled oscillators (VCOs). The first member of this new line of integrated VCOs is aimed at handling triple bands in the cellular arena. The LMX2604 is tailored to meet the specifications for the GSM and GPRS cellular standards. In fact, the small form factor and low phase noise of the device are designed for GSM900/DCS1800/PCS1900 triple-band applications.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"></div><table border="0" cellpadding="5" cellspacing="0" style="font-family: Georgia,"Times New Roman",serif; margin-left: 0px; margin-right: 0px; text-align: left; width: 140px;"><tbody>
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</tbody></table><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><a href="http://rfdesign.com/mag/jan04pom.gif" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://rfdesign.com/mag/jan04pom.gif" /></a> In essence, the LMX2604 chip incorporates two VCOs, one for GSM in the 880 MHz to 915 MHz range and a second one for DCS in the 1710 MHz to 1785 MHz band and PCS in the 1850 to 1910 MHz band. In addition, it offers two separate buffer amplifiers to drive an external high-power amplifier, one for the GSM900 band and the other for DCS1800/PCS1900 bands. Furthermore, the monolithic VCO provides a differential buffer amplifier to drive the mixer in offset PLL (see the figure)<b>.</b> The resonant circuits of the VCOs are fully integrated on the chip to ease the application of the IC. The oscillator core and the tank circuit are designed to be immune to external noise such as supply and load variations. According to the manufacturer, the high quality factor of the embedded tank circuit achieves very low phase noise characteristics at the VCO output. It has low phase noise of -167 dBc/Hz at 20 MHz offset in the GSM band, and -162 dBc/Hz at 20 MHz offset in the DCS and PCS bands. The only required external components are a couple of supply bypass capacitors and matching components. A control pin for controlling the oscillation frequency is shared by the two VCOs. The new VCO exploits 0.25 µm RF CMOS process for integration.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">High output power for the integrated VCO is +6 dBm in all bands, which is ideal for use with transmit closed-loop modulation. The LMX2604 also has 2.7 V to 3.3 V operation and low current consumption of 18 mA in GSM mode and 15 mA in DCS/PCS mode. Other salient features of the device include smaller package and fewer external components. To provide a smaller package than alternative triple-band VCO modules, the LMX2604 is housed in a 20-pin leadless leadframe package (LLP), which is 4 × 4 mm in size. This allows designers to save significant board space in mobile handsets. The supplier also has plans to offer additional members in this line throughout the year. Available now, it is priced at $1.35 in 1,000 units.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Bibliografia: http://rfdesign.com/vlf_to_uhf/rf_circuits/radio_monolithic_vco_tackles/</b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/monolithic-vco-tackles-triple-bands.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T19:33:00-07:00">19:33</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=5185243532665508099" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=5185243532665508099" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-25944956531433072752010-07-17T21:57:00.002-04:302010-07-25T08:43:08.703-04:30Commercial-off-the-shelf MMIC components offer high reliability<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Demands on reliability of commercial-off-the-shelf (COTS) components are increasing. Responding to this need, Mini-Circuits has instituted rigorous new design guidelines and reliability inspection verifications to ensure Mini-Circuits components will last longer than the lifetime of the customer's end product. This paper presents the details of design and quality assurance programs, which will help designers decide on incorporating COTS components into their military or other high-reliability applications.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The life of semiconductor products is a function of junction temperature. The hotter the junction gets, the shorter will be the life. Unless a product is properly designed, no amount of testing will ensure reliability. Packaging materials should include specially developed lead frames and highly heat-conductive die-bond epoxies and mold compounds to efficiently dissipate heat.<br />
<br />
Die designers need to ensure low junction temperature by:</div><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li>Using bigger devices or several small devices connected in parallel to spread the heat.</li>
</ul><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li>Laying out the die so as to physically separate the heat-generating elements.</li>
</ul><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
Using bigger devices tends to degrade high-frequency performance. With smaller devices in parallel, one needs to ensure that power is combined in such a way that manufacturing tolerance does not favor current flow in one device over another, as this can result in overheating and thermal runaway.<br />
<br />
Theoretical prediction of junction temperature is the first step in the design. Three-dimensional finite element modeling of the die and package is one of the methods used to analyze heat distribution and predict hot spot temperatures.<br />
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After the die is manufactured, it is packaged. Packaged devices are selectively etched to expose the die while retaining the mechanical integrity of the device. High-resolution infrared images are then taken to validate the thermal predictions. Figure 1 shows the infrared thermal image of a medium-power gain block amplifier.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNwskUGL1siWtHvkyeeuVI5oJlbnisClcthXLzgiGadHcZZtJ2kROCA0RlmzU6GC2wGFt3BSIcm1QQ7PQ7XWAbPwnwl7Z8TVKZeeswQgFEb89VqkUSlXtcOb03znRy51EmMg2JDsC3jrM/s1600/cosas10.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNwskUGL1siWtHvkyeeuVI5oJlbnisClcthXLzgiGadHcZZtJ2kROCA0RlmzU6GC2wGFt3BSIcm1QQ7PQ7XWAbPwnwl7Z8TVKZeeswQgFEb89VqkUSlXtcOb03znRy51EmMg2JDsC3jrM/s320/cosas10.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">This image is taken with the device package mounted on a base plate with temperature held at 85° C, which is the highest specified ambient operating temperature of the device. It is a good practice to add another 5° C or 10° C to this temperature to account for the temperature rise of the user's printed circuit board (PCB) over the ambient. Most of the dice are designed to have hot spot temperature less than 130° C at the highest specified ambient.<br />
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Important information required for mean time to failure (MTTF) prediction is the relationship of MTTF to hot spot temperature. Standard industry practice is to perform accelerated life tests to derive this relationship. Circuit designers should, therefore, use the device-specific MTTF graph given in data sheets (example: Figure 2), instead of general prediction models such as MIL-HDBK-217 (reliability prediction of electronic equipment). Those models tend to give overly pessimistic values for modern commercial semiconductor devices.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinEnsi6txTLifjLMl0W-QF74GBB_WhOUPs8H87uagg12ZADg9Sbo8j_rqwOcIODcNwIYdKmXFQRAjoZbWzJY0Os5WDtMPQnLRpgwSrW1AwD3Iwi8NTxvdtGYJHl9hvc6wKT7ZwtfzGOLs/s1600/cosas11.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinEnsi6txTLifjLMl0W-QF74GBB_WhOUPs8H87uagg12ZADg9Sbo8j_rqwOcIODcNwIYdKmXFQRAjoZbWzJY0Os5WDtMPQnLRpgwSrW1AwD3Iwi8NTxvdtGYJHl9hvc6wKT7ZwtfzGOLs/s320/cosas11.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 2</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Figure 2 shows MTTF vs. junction temperature for HBT devices such as Mini-Circuits ERA and Gali series amplifiers as an example. Note the MTTF of the device shown in Figure 1 is about 500 years at 85° C ambient temperature, which is adequate for most applications. To increase reliability, lower device current needs to be used (readily accomplished as this is a current-controlled amplifier) at the expense of lower output power.<br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHpLQKDUuLSlKSTXSjV4AfhcB1YtSb98Qm9IWPdstkUuJX_eDSuJSAcNz4BUNZuQUbX6FTjm5QQ1xq1TarVtvATcmvbLh50cKTALFBa0TzKGSBZ7J-IxKKAKNH0MZNxuK4J4Z7KnxKKAU/s1600/tabla1.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="166" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHpLQKDUuLSlKSTXSjV4AfhcB1YtSb98Qm9IWPdstkUuJX_eDSuJSAcNz4BUNZuQUbX6FTjm5QQ1xq1TarVtvATcmvbLh50cKTALFBa0TzKGSBZ7J-IxKKAKNH0MZNxuK4J4Z7KnxKKAU/s400/tabla1.JPG" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"> <span style="font-size: large;"><b>Package design and reliability verification</b></span><br />
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Vapor pressure of moisture inside a non-hermetic package increases greatly when the package is exposed to moisture followed by the high temperature of solder reflow[3].<br />
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A proprietary technique has been developed to prevent delamination, after years of research, and has been qualified to meet J-STD-020C.<br />
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A scanning acoustic microscope (SAM) is used during qualification and process monitoring to detect delamination. The operation of SAM is based on simple acoustic principles. The devices under examination are submerged in a large container of de-ionized water. An ultrasonic transducer is placed near the surface of the device below the water line. The transducer generates a series of high-frequency waves that impinge upon the various package components. The acoustic wave will penetrate, and will be reflected fully or partially based on the nature of the material; the transducer detects the reflections. Based on the amplitudes and the phases of the reflected waves, the acoustic microscope can detect internal package cracks, die cracks, tilted die, voids in the die attach and interface delaminations.<br />
<br />
Table 1 lists the tests, criteria, standard and sample size used. Figure 3 is a flow chart of the tests. Peak reflow temperature in the moisture sensitivity level (MSL) test is 260° C, which corresponds to the peak reflow temperature used with lead-free solders.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm89sv4JkjZacGLAJeiuRz2e_OJfy7ExmqCJ6VuP5Q4syjp4o0NS4s0uRlZCyNwbqOOYHx0yXE5_a1TjUlOqlT6KKpR3jlno7zL-yctLLROu48-f2ohq-TPmfqUWibkD6DTCyOPEahdwY/s1600/figura3.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm89sv4JkjZacGLAJeiuRz2e_OJfy7ExmqCJ6VuP5Q4syjp4o0NS4s0uRlZCyNwbqOOYHx0yXE5_a1TjUlOqlT6KKpR3jlno7zL-yctLLROu48-f2ohq-TPmfqUWibkD6DTCyOPEahdwY/s320/figura3.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 3</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Figure 4a shows SAM images of an array of units of conventional design that have undergone MSL tests per Table 1. Red indicates delamination. Note 20 of 22 units have delamination.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrjdY-Dz_r1cYqlpRDpferRARbxHPpL_brIvOpLbLLD5KyqO1WdkLLJJTxqbHPfPzZmkpkh3-uDvtyfmgHCAeyTSYhnrpkwBDwZf1jNBkqEgL8R7C13yTZIWCVgQhrylPtulWdUyiuCWw/s1600/figura4a.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrjdY-Dz_r1cYqlpRDpferRARbxHPpL_brIvOpLbLLD5KyqO1WdkLLJJTxqbHPfPzZmkpkh3-uDvtyfmgHCAeyTSYhnrpkwBDwZf1jNBkqEgL8R7C13yTZIWCVgQhrylPtulWdUyiuCWw/s320/figura4a.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 4a</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Figure 4b shows the SAM image of an array of units of improved design, which have undergone MSL tests per Table 1. No unit failed.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiUvHIN75r9V2ulfGJgfb7An2imetBYutBFr9rFGT4zIdq7wArC6bSVQe5NCcYe7uJN0SigN5Fy78BDGRi0mGSrqgNRo_YGnsY2_eQKHeYaEE3YG1Nqd-WfZXVzBdqv5_rLCUxayLfBE0/s1600/figura4b.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiUvHIN75r9V2ulfGJgfb7An2imetBYutBFr9rFGT4zIdq7wArC6bSVQe5NCcYe7uJN0SigN5Fy78BDGRi0mGSrqgNRo_YGnsY2_eQKHeYaEE3YG1Nqd-WfZXVzBdqv5_rLCUxayLfBE0/s320/figura4b.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 4b</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">JEDEC spec[3] allows certain types of delaminations as long as the units pass electrical tests. Our criterion for success is units should pass the moisture absorption tests and C-SAM to show no voids at all. Voids affect thermal resistance as heat is dissipated from the junction to the ambient through the package. Most of the heat is dissipated through the die onto the lead frame on which it sits. Thus, the improved design package is of great value for applications requiring the devices to perform reliably for a long period of time, such as for the military.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
<span style="font-size: large;"><b>Thermometer inside</b></span><br />
<br />
Diode forward voltage varies with temperature. This characteristic is used to measure die hot spot temperature for each lot. For each MMIC amplifier product, a special die is designed that has a thermal-sensing diode close to the die hot spot. This die is part of each reticle and will, therefore, undergo similar process variations as the regular die under investigation. The special die is packaged and powered, a small current is passed through the diode, and diode voltage is measured to determine the hot spot temperature. Figure 5 shows hot spot temperature of a typical device. This type of quality assurance test ensures the thermal resistance is a parameter of concern, and any change will trigger a review and process changes if required to bring it under control.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNBXtU3nS8RQ5CMrVHRCLmtGICEwG6Auf4ZOUik_NMjMnK4-jaYYaz1lyhgFAbJl4AXlbVbRSzmGfhYLCXk3n79YV5Irdq0N6rhGvqRo0BVWBZzh3Clf5D3Xgx6YJkwTaP1l0rZaUAEGA/s1600/figura5.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNBXtU3nS8RQ5CMrVHRCLmtGICEwG6Auf4ZOUik_NMjMnK4-jaYYaz1lyhgFAbJl4AXlbVbRSzmGfhYLCXk3n79YV5Irdq0N6rhGvqRo0BVWBZzh3Clf5D3Xgx6YJkwTaP1l0rZaUAEGA/s320/figura5.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 5</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>Extended HTOL tests</b></span><br />
<br />
Some manufacturers subject samples to life tests at maximum specified ambient temperature for 1000 hours. We use 125° C ambient, which is 40° C above the 85° C maximum ambient specified, and which is also used by other quality-conscious manufacturers. What distinguishes Mini-Circuits is the use of extended life test for 5000 hours instead of 1000 hours. This tough life test would bring out defects that ordinarily would not be caught. The disadvantage of this process is that it takes a long time to correct design defects. In order to minimize design cycle time, small manufactured lots go through these tests and results are used to correct the design of production lots.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>X-ray inspection</b></span><br />
<br />
X-ray equipment is used in the assembly process as a process control monitor to look for wire sweeps at molding or wire bond defects. Figure 6 shows an assembly defect. Such information is used for applying corrections to manufacturing processes in real time.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6YgOwuy_9dibreY7CVo6EjdUkyb_uME263X_5QHThGcVFmtwNnM2OzV8sotNDL0QMQ-mkd6Xz5jpNsjhyKYSte63Xolt-McZ-bJcmgbtelqm-hnbS3LbjnEYEelPB5SY4CSA2NPT1kTQ/s1600/figura6.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6YgOwuy_9dibreY7CVo6EjdUkyb_uME263X_5QHThGcVFmtwNnM2OzV8sotNDL0QMQ-mkd6Xz5jpNsjhyKYSte63Xolt-McZ-bJcmgbtelqm-hnbS3LbjnEYEelPB5SY4CSA2NPT1kTQ/s320/figura6.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 6</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>S-parameter tests for each manufacturing lot</b></span><br />
<br />
Most manufacturers test S-parameters during qualification on one sample, and rarely on a few samples, irrespective of the production quantities. Production tests are at spot frequencies and for few parameters such as gain and dc current.<br />
<br />
At Mini-Circuits, we believe variations need to be continuously monitored. For this purpose, each manufacturing lot of the devices undergoes full S-parameter tests. The data is compared to a golden sample from the original qualification lot. This enables a tight process control on variations of parameters that may affect our customers' applications. Figures 7 and 8 are examples of plots obtained</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqCdUdnyCEV0PZN25k76dxdZO9a884qWjrM_lMo1yp_BERhHwJAD2WQOwLkrPwrCPNOLfVOKkLghFJrrEtANarpL2aHfNBG5skA4vsdnsYIMez_0pN5jY2Fnxrd65wNd2YIFChTVl2IFc/s1600/figura7.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqCdUdnyCEV0PZN25k76dxdZO9a884qWjrM_lMo1yp_BERhHwJAD2WQOwLkrPwrCPNOLfVOKkLghFJrrEtANarpL2aHfNBG5skA4vsdnsYIMez_0pN5jY2Fnxrd65wNd2YIFChTVl2IFc/s320/figura7.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 7</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1YaUHv5KXRg3Au5RAsXK2QNjfm1P0Dgw6JueyAUt63-MWg7DKQSd8rbCrPkZsEVUynHET0KSy3PLOVMiq-ZwEmLkzbPZ8WNeIuCQ-rp_2zpe9epLFL3rKZ6l_2PozTzaLD_SxAouIuVQ/s1600/figura8.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1YaUHv5KXRg3Au5RAsXK2QNjfm1P0Dgw6JueyAUt63-MWg7DKQSd8rbCrPkZsEVUynHET0KSy3PLOVMiq-ZwEmLkzbPZ8WNeIuCQ-rp_2zpe9epLFL3rKZ6l_2PozTzaLD_SxAouIuVQ/s320/figura8.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"> Figure 8</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>Qualification tests</b></span><br />
<br />
Industry-standard qualification tests are done in addition to the aforementioned tests. These include HTOL, HAST, vibration and shock, and thermal cycling and satisfy traditional qualification requirements of the industry.<br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif; font-size: large;"><b>Conclusion</b></span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Demands on quality of very high volume commercial products exceed the requirements specified for most military products.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Extensive reliability and physical analysis capabilities at the assembly operations such as C-SAM tests and X-ray inspection are used not only for product qualification and failure analysis but also for in-process quality and reliability monitors. This gives real-time data to manufacturing for process controls to ensure production of a high-quality product.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Mini-Circuits employs traditional qualification tests, extended life tests and lot S-parameter characterization to ensure that the quality and electrical performance of the product far exceeds the requirements of commercial products. Designers of military products should closely review the quality of commercial-off-the-shelf products produced by quality-conscious manufacturers to save money and time in high-quality component procurement.</span></div><div style="text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://rfdesign.com/ar/0205rfdefensef2.pdf</span></b></div><div style="text-align: center;"><br />
</div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/commercial-off-shelf-mmic-components.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T19:25:00-07:00">19:25</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=5920178576231248223" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=5920178576231248223" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-67981558858273471752010-07-17T21:29:00.002-04:302010-07-25T08:42:45.115-04:30A general measurement technique for determining RF immunity<div class="post-body entry-content"><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">The presence of the radio-frequency (RF) environment is steadily progressing due to the ubiquitous usage of cell phones. An electronic circuit under such RF environments can give distorted results owing to the circuit's poor RF rejection capability. In order to have the electronic circuits working satisfactorily it becomes imperative to test for its RF immunity.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">This article describes a generalized technique to measure the RF immunity of a circuit. It defines a standard and structured test methodology aimed at establishing adequate repeatability of the test results for qualitative analysis. The test results thus obtained aids in astute selection of ICs and developing circuits that are less prone to RF noise.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The RF susceptibility can be tested by placing the DUT near the cell phone. But to have accurate, comparable and efficacious test results the DUT needs to be tested in consistent and repeatable RF fields.The RF anechoic test chamber produces such RF fields that are accurately controlled and comparable to that generated by a typical mobile phone. The RF immunity test procedure was carried on MAX4232 and competitor's parts (Part X) and its results were compared.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The circuit diagram in Figure 1 shows the circuit board connections to the dual op-amp under test in the RF setup. The op-amps are configured as an ac amplifier. With no ac signal, the output sits at 1.5 Vdc (with a supply voltage of 3 V). The inverting input is shorted to ground using 1.5-inch loop of wire to emulate the actual trace of wire to the input signal. This loop incorporates the effects of the actual trace, which could probably be acting as an antenna at the working frequency, collecting the RF signal and demodulating it. The RF noise immunity of the op-amp is measured and quantified by connecting a dBV meter at the outputs of the op-amp.</span></div><div style="text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLtpK-dEAXk-A61qbU6klmHA9e6t4pSBcvV1zOblogunjsaDfYbQaGtWRTl8GTry6xwi7ET4QhAUkhKK9_LGz-Mq5ui6kalKmeP6wVVneuS6IEVku7C6JtcDILWfwfb-dLD1XEm8WjClg/s1600/cosas7.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLtpK-dEAXk-A61qbU6klmHA9e6t4pSBcvV1zOblogunjsaDfYbQaGtWRTl8GTry6xwi7ET4QhAUkhKK9_LGz-Mq5ui6kalKmeP6wVVneuS6IEVku7C6JtcDILWfwfb-dLD1XEm8WjClg/s400/cosas7.JPG" width="321" /></a></div><div style="text-align: justify;"><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1</div><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Figure 2 shows the RF anechoic test setup system that emulates the RF field environment necessary for RF immunity testing. This test chamber is similar to a "Faraday's Cage" and has a shielded body. The chamber has access ports for connecting supply voltages and output monitors. The setup is formed by concatenation of the following equipment:</span><span style="font-family: Georgia, 'Times New Roman', serif;"></span><br />
<ul><li><span style="font-family: Georgia, 'Times New Roman', serif;">Signal generator: SML-03, 9 kHz to 3.3 GHz (Rhode & Schwarz)</span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">RF power amplifier: 800 MHz-1 GHz/20 W (OPHIR 5124)</span><span style="font-family: Georgia, 'Times New Roman', serif;"></span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">Power meter: 25 MHz to 1 GHz (Rhode & Schwarz);</span><span style="font-family: Georgia, 'Times New Roman', serif;"></span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">Parallel wired cell (Anechoic chamber);</span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;"> Electric field sensor</span><span style="font-family: Georgia, 'Times New Roman', serif;"></span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">Computer (PC); and</span><span style="font-family: Georgia, 'Times New Roman', serif;"></span><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">dBV meter.</span></li>
</ul></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDkHqqqwmywksAu50zPaIUJupXWBuPTtcknlB5XHcToCVVWfqBD6-8SWd3w0uby_8FfmT38Di68VEfo4LPaYdxGPGxgkNaRIHEEgENGjwC1tvt2Y8Fb8B99VMT8T_t12o57lhXPOW_YAs/s1600/cosas8.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDkHqqqwmywksAu50zPaIUJupXWBuPTtcknlB5XHcToCVVWfqBD6-8SWd3w0uby_8FfmT38Di68VEfo4LPaYdxGPGxgkNaRIHEEgENGjwC1tvt2Y8Fb8B99VMT8T_t12o57lhXPOW_YAs/s320/cosas8.JPG" /></a></div><div style="text-align: justify;"><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 2</div></div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">The signal generator generates the RF signal of the desired frequency and modulation and is fed to the power amplifier. The amplifier output is measured and monitored with a directional coupler in conjunction with a power meter. The computer controls the range of frequencies applied from the output of the signal generator, its modulation type, modulation percentage and its power from power amplifier output so as to generate the desired RF field. This field is radiated inside the chamber using an antenna (planer).</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">To perform the immunity test on MAX4232 vs. Part X, the DUT is placed inside the shielded anechoic chamber, which serves best to produce uniform, accurately calibrated and consistently repeatable electric fields.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The RF field experienced by a DUT placed near a typical cell phone is around 60 V/m at about 4 cm from the radiating antenna of the phone and decreases as one moves the DUT away from the phone (around 25 V/m at a distance of 10 cm from the phone). A uniform field strength of 60 V/m is generated to emulate the actual RF environment experienced by a DUT. Also, 60 V/m is low enough to keep the receiving devices below the clipping level and avoid measurement errors. A RF sine wave whose frequency is varied between the cell phone frequencies of 800 MHz to 1 GHz is modulated with an audio frequency of 1000 Hz with 100% modulation. Modulation with 217 Hz would have produced similar results but a more common 1000 Hz audio frequency is chosen. The access ports on the side of the chamber serve to provide power to the DUT and also to connect the dBV meter, which is set to give dBV (dB's relative to 1 V) readings. Furthermore, the RF field can be accurately calibrated by locating the position of the DUT using the field sensor.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Figure 3 depicts an average output of MAX4232 and Part X. Under the RF frequency variation from 800 MHz to 1 GHz with a uniform electric field of 60 V/m, MAX 4232 shows -66 dBV (500 µV rms with respect to 1 V) and that of Part X is -18 dBV (125 mV rms with respect to 1 V). In the absence of any RF signal, the dBV meter shows -86 dBV.</span><br />
<span style="font-family: Georgia, 'Times New Roman', serif;"></span></div><div style="text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilvrIAJi-PPW0z_KULg28rG2DWWF3grDf6LUe1d16WPQBm8ythyDH_DPzL5PtbDgaTnBdb8F84ffTrbXQDzkZfS6ykkUyY_k6J3YxRBFgdEMm5UPMSaGvT_on4yAS3wHqiciPllcL7qQ4/s1600/cosas9.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilvrIAJi-PPW0z_KULg28rG2DWWF3grDf6LUe1d16WPQBm8ythyDH_DPzL5PtbDgaTnBdb8F84ffTrbXQDzkZfS6ykkUyY_k6J3YxRBFgdEMm5UPMSaGvT_on4yAS3wHqiciPllcL7qQ4/s320/cosas9.JPG" /></a></div><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;"> Figure 3</span></div><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;"><br />
</span></div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">Thus, MAX4232 output changes by only -20 dB [(-86 dBV) — (-66 dBV)] or goes from 50 µV rms to 500 µV rms under the influence of RF environment. We can say that the output of MAX4232 changes by only a factor of 10 under the selected RF environment. Hence, it can be concluded that MAX4232 has excellent RF immunity of -66 dBV and would not produce any major noticeable distortion at the output.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">However, the average reading of Part X is only -18 dBV, which means that this part under RF influence shows 125 mV rms with respect to 1 V rms, a major perceptible increase by 2500 times than the normal expected 50 µV rms. Thus, part X can be said to have a poor RF immunity of -18 dBV and is more likely to cause problems in close proximity to cell phones and other RF sources.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Hence for applications that need the processing of audio signals such as headphone amplifiers, mic amplifiers, op-amps with high RF immunity are better suited.</span></div><div style="text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://rfdesign.com/mag/510RFD33.pdf</span></b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/general-measurement-technique-for.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T18:58:00-07:00">18:58</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=1743141950794484269" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=1743141950794484269" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-47004376513636945112010-07-17T20:57:00.001-04:302010-07-25T08:42:22.074-04:30Channeling Power In MW Components<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">High-power levels are a reality in many high-frequency transmitter systems, and components suppliers are now being asked to supply products that can handle the heat in smaller housings.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">Handling large amounts of RF/microwave power is part science, part imagination. The science exists in the form of thermal flow equations and thermalmechanical design software programs to calculate temperature rises in a wide range of electronic materials based on input power levels, dissipative and radiative losses, and thermal conductivity, among other parameters. The imagination helps to visualize the thermal flow through a system and, hopefully, to identify potential hotspots.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">This article will consider the high-power levels associated with transmitters, such as terrestrial and satellite communications systems and in radar and electronicwarfare (EW) systems and a sampling of products developed for these systems. Such power levels are often in the range of hundreds to thousands of watts, and require the use of the largest transistors and vacuum electronics, such as traveling-wave-tube amplifiers (TWTAs), to deliver required power levels to a transmit antenna.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">High-power signal generation in military radar systems has traditionally relied on vacuum electronic devices, such as magnetrons and TWTAs, although the US Department of Defense (DoD) and other international defense agencies have funded the development of solidstate alternatives capable of producing over 100 W average (continuous) and peak (pulsed) output power. Earlier this year, Microsemi Corp. (introduced its model 0405SC- 1500M 1.5-kW UHF transistor-based on silicon-carbide (SiC) substrate material. Designed for pulsed radars, the common-gate Class AB device delivers 1500 W output power from 406 to 450 MHz when operating with 300-µs pulses at 6-percent duty cycle.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">At higher frequencies, the NPT1007 transistor from Nitronex, which is based on gallium nitride (GaN) substrate material, is usable to 1200 MHz. It achieves 200 W output power at 900 MHz with 18.3 dB gain. The device combines the output power of two separate transistors housed within a four-lead Gemini package with 18.3 dB gain and 63 percent efficiency.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Although transistors have gained in power, tube amplifiers, such as the model dB-4522 TWTA from dB Control, continue to supply high power levels while shrinking in size. The dB-4522 operates from 11 to 18 GHz. It delivers 450 W CW output power from11.0 to 17.5 GHz and 400 W CW output power from 17.5 to 18.0 GHz.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Designers of passive components must also follow the trend of higher power levels in smaller packages, in order to help miniaturize commercial systems such as communications cellular base stations and military systems such as communications and radar systems on unmanned aerial vehicles (UAVs). Because of the small size of high-frequency passive components, such as hybrid couplers, dissipating heat becomes a major issue even at tens of watts. EMC Technology, for example, recently introduced a line of chemical-vapordeposition (CVD) fabricated diamond chip resistors and terminations for applications through 26.5 GHz. Resistor models are capable of power levels to 150 W through 12.4 GHz while terminations, such as the model CTO603D, can operate to 18 GHz with 80 W power. This 50-O termination measures only 1.65 x 0.89 x 0.38 mm.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The newest generation of Xinger passive components from Anaren Microwave includes hybrid couplers measuring just 0.25 x 0.20 in., with models capable of handling more than 180 W CW power at 1 GHz .They were tested and modeled with thermal analysis tools (see figure) to study the thermal flow through the components. Such studies revealed that the use of plated viaholes made a significant difference in lowering temperatures at high power levels.</span></div><div style="text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22810/fig_01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="232" src="http://mwrf.com/files/30/22810/fig_01.jpg" width="320" /></a></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">For thermal studies at high power levels, component designers typically use programs from SolidWorks, Thermal Desktop, RadCAD, and FloCAD from C & R Technologies, Icepak from ANSYS, and FloTHERM PCB from Mentor Graphics. For example, highpower component and subassembly developer Micronetics has applied SolidWorks to its analysis of high-power PIN switches. The firm's thermal management strategy aims at maintaining safe diode junction temperatures at high power levels.<br />
<br />
Along with thermal simulations at high power levels, measurements are also an essential part of high-power design, and a long-invaluable tool has been the pairing of a microwave power meter and power sensor. A number of suppliers offer quality products in this area, for testing CW and pulsed power levels through millimeter-wave frequencies, including Agilent Technologies, Anritsu, Giga-tronics, Krytar, Ladybug Technologies , Rohde & Schwarz, and Boonton Electronics.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</span></b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://mwrf.com/Article/ArticleID/22810/22810.html</span></b></div><div style="text-align: justify;"><br />
</div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/channeling-power-in-mw-components.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T18:26:00-07:00">18:26</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=4192045245943333982" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=4192045245943333982" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-33916853277752304762010-07-17T20:47:00.002-04:302010-07-25T08:41:53.890-04:30Mixing RF, digital and analog circuits on the same PCB<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A dynamic link integrates the PCB schematic and layout tool with RF design and simulation tools, resulting in a solution that overcomes the shortcomings of the classic RF design.<br />
<br />
The presence of RF circuitry on printed circuit boards (PCBs) was once limited to military and aerospace industry requirements. Now, the proliferation of the wireless handheld communications and remote-control devices is driving the need for mixed analog, digital and RF designs at a significantly increasing rate. Handhelds, base stations, remote controls, Bluetooth devices, computer wireless, many consumer devices, and mil/aero systems now all contain RF.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">For years, RF design has been a special art, requiring specialized design and analysis tools, used by specialized designers. Typically, the RF portion of a PCB was designed by that specialist in a separate environment and then merged into the rest of the mixed-technology PCB. This process was highly inefficient, often required iterations to marry the mixed technologies together and resulted in multiple, unrelated databases representing the final product.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>RF design paradigm has changed</b></span><br />
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In the past, design functionality was performed (and repeated) in two design environments through non-intelligent ASCII interfaces (Figure 1). Both the PCB system design and the RF specialized design systems had their own libraries, RF design databases, and design archiving. It required that design data (schematic and layout) and libraries be managed (and synchronized) in both environments through the cumbersome ASCII interfaces.</div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="237" src="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure01.jpg" width="320" /></a></div><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;">Figure 1</span></div><br />
<div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">With this old methodology, the RF designer was developing the RF circuitry isolated from the rest of the PCB system design. The RF portion was then translated into the PCB design using ASCII files to create schematic and physical implementation on the host PCB. If problems exist with the RF circuitry, the design must be corrected in the stand-alone RF solution and re-translated into the host PCB. The result was a total replacement versus an incremental change.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">RF simulators only simulate the ideal RF circuit. The actual implementation in the mixed system with fractioned ground planes, ground vias and neighboring RF circuitry has been extremely difficult to analyze and it's well known that these additional shapes will have a profound impact on the RF circuit operation.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">This old methodology has been used successfully for years to design mixed-technology boards, but as the RF content in products increases, the problems with having two separate design systems is starting to impact designer productivity, time-to-market, and quality of the products.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">With these issues in mind, Mentor Graphics has developed a dynamic link that integrates the PCB schematic and layout tool with RF design and simulation tools, resulting in a solution that overcomes the shortcomings of the classic RF design. Working with RF design experts, a set of requirements was identified and a new solution designed.</span><br />
</div><div style="text-align: justify;"><span style="font-size: large;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">RF-aware PCB design</span></b></span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">No integration — no matter how good — can help maintain design intent between PCB design and RF design unless there is a common understanding of the technology-specific environment between the tool sets. In other words, the typical layer-oriented structures in PCB layout has to be understood by the RF design tools and the parametric planar microwave elements used in the RF design environment must be understood by the PCB system.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Another key issue is that PCB systems regard RF shapes as short circuits and this prevents proper design rule checks (DRC) of the design. With today's complex RF system designs, functional RF aware DRC is a must to enable a correct by design methodology.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">All these contribute to the design intent. Preserved design intent is critical as this is the foundation to support multiple iterative roundtrips of design data between tools without losing information.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">RF design is an iterative process. A design is tweaked or optimized in many steps. It was difficult in the past to do this in the context of the real PCB design. When the optimized RF module was implemented on the PCB, there was no guarantee that it would still work in an optimal manner. As a validation, the PCB implementation was sent to electromagnetic field analysis (EM).</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">This design flow has several problems. First, the circuit is pushed to simulation as simple metal polygons, so there is no way to modify the metal in the RF tool and send the optimized result back to PCB design and still have an intelligent RF circuit. Second, EM solutions are time consuming so it may be best to wait until it's needed.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">In the new flow, as the PCB and RF tools share an understanding of the design intent, the circuit can be looped back and forth between the tool sets multiple times without loss of design intent. This means that circuit simulation (which is very fast) and EM analysis (when needed) can be repeated and results can be compared for every change made to the circuit. This is done within the context of the real PCB with fractioned ground planes, RF shapes, traces, vias, and other components.</span><br />
</div><div style="text-align: justify;"><span style="font-size: large;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Libraries: Garbage in, garbage out</span></b></span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Libraries have always been a hurdle in RF system design. The standard components in the RF library (capacitors, resistors, transistors, etc.) frequently lack some of the parameters required for the PCB design and manufacturing processes. Likewise, the PCB design libraries usually don't contain the planar microwave elements used in the RF domain to build up RF circuitry.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">In the past, a snapshot has been taken of the microwave element library, but as with any snapshot, it could be outdated in no time, forcing designers to manually ascertain that the PCB and microwave library is kept in absolute synchronization. And not just synchronized, but perfectly synchronized to ensure performance on the PCB is 100% identical to what you simulate. Obviously, as this process involved people, it failed now and then. The new integration solves this dilemma using an inter-tool dynamic link to synchronize the library.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">With the foundation in place, the integration between the RF design tool and PCB needed an overhaul. For more than 10 years, this integration has been based on two-way translation of ASCII IFF-format files. Although, capable of holding a portion of the design data, this format is far from adequate to support seamless round-trip integration. Lack of library synchronization is one of the more critical issues. RF and board designers have struggled with this model for a long time and despite attempts to improve the interfaces only marginal results were seen.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Something different had to be developed and this led to a network-based inter-tool communication providing a dynamic two-way link between RF design and system-level PCB design (Figure 2). To support concurrent engineering processes, multiple board designers can operate simultaneously on the same design database and each link to one or multiple simulation sessions. Now an RF module can be designed in the RF design tool and, when appropriate, be pushed over and become an intelligently integrated part of the system-level schematic and PC board rather than the black box circuit of the past. At this stage, circuit updates can be made in either environment and the impact be simulated.</span><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure02.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="230" src="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure02.jpg" width="320" /></a></div><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;"> Figure 2</span></div><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;"><br />
</span></div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">Each RF circuit is contained as a grouped object to help maintain traceability, version management and design reuse. As design intent is preserved, any number of iterations can be processed without the usual cost in cycle time. Also, as the RF module can be simulated within the context of the actual system-level PCB, its function can be validated at a more detailed level to help cut design cycles.</span><br />
</div><div style="text-align: justify;"><b><span style="font-size: large;"><span style="font-family: Georgia, 'Times New Roman', serif;">RF PCB bottlenecks</span></span></b><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">There are several well-known RF PCB design bottlenecks. First, as each RF module on a board may have been designed by a separate RF design team and the module may live its own life in terms of versioning, variants and reuse, it becomes vital to be able to manage the circuit as a group that can be managed as one entity and its origin and version be traced — but still be accessed as individual circuit elements at any time. To resolve this issue, the schematic and layout tools were expanded to support hierarchical circuit grouping. This way, even though an RF circuit is laid out on a PCB, it is still kept together as an RF circuit and can be linked to the proper RF team for analysis.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The next hurdle is ground plane clearance. In the classic design process, the RF metal was imported as a black box piece of metal and ground clearance was handcrafted as plane voids on every layer needed. When the RF circuit was updated — which was a frequent operation — the cutouts had to be manually edited to reflect the new circuit. This edit process alone can take weeks for some designs.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">With a new design flow that promotes iterative updates between RF design and PCB design; manual updating is too slow. Instead, an intelligent parametric RF shape clearance is introduced to let the RF circuit clear ground the way the RF engineer defines it, and to have it parametrically updated as the RF circuit evolves during design, as shown in Figure 3. This parametric plane clearance cannot only be defined for the same layer on which the RF shape is placed, but also for layers above and below the shape, including the solder mask. If the RF circuit is updated with changed dimensions or if it's being moved to a new layer, these cutouts automatically update, saving a tremendous amount of cycle time.</span></div><div style="text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure03.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="268" src="http://rfdesign.com/rfic/design_tools/0508RFD-RF-digital-analog-PCB-Figure03.jpg" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 3</div><div style="text-align: justify;"><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Interconnection between RF elements on the PCB typically uses meander lines instead of normal PCB traces to connect RF circuits. These meander lines can have tapered width changes, optimal impedance miter, or curved bends.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">In the past these were made as metal plane shapes and were difficult to edit. Furthermore, as they were metal polygons, the only way to simulate was to use a time-consuming EM solution. Mentor has solved this dilemma by designing a meander line design object for its PCB tools. This way, the PCB designer can connect RF signals effectively and when simulation is needed, the meander lines can be sent to EM analysis — as in the past — or automatically be decomposed into fast circuit models.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">A striking feature of most RF system designs is the very large number of via holes stitched along RF shapes, around plane contours or peppered over plane surfaces.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">This so-called via stitching is used to reduce radiation losses when stitched along RF shapes or when peppered across planes, to prevent parallel plane excitation.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Adding these vias manually costs countless hours or days and need manual rework each time the circuit is updated in design iteration. Many board designers developed smart scripts and programs to add the vias but the issue with rework is still unsolved.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Now, designers can automatically generate via patterns and contour stitching parametrically in elaborate patterns, multirow stitching along shapes, and include them in the EM simulation (Figure 3).</span><br />
</div><div style="text-align: justify;"><b><span style="font-size: large;"><span style="font-family: Georgia, 'Times New Roman', serif;">Conclusion</span></span></b><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The new RF design paradigm has put RF design companies in a tricky situation with unacceptable cycle time and excessive design cycles. We are now working with RF tool vendors at a different level than what has been the norm in order to provide a design flow that is tailored to meet the challenges seen in the industry today and in the future.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The prime goal — to cut design cycles — is reached by ensuring a synchronized library and by facilitating a fast and easy integrated simulation flow. As designers can simulate frequently as the design evolves, the system can be validated up front. RF-aware DRC promoting correct by design also contributes.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Cycle time was traditionally wasted in cumbersome file translation between tools and in the fact that the PCB tools did not understand RF or even support some of the primary RF design requirements.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">ASCII file transfer is a relic of the past. The demand for integrated design teams across technology and global boundaries dictates direct tool integration where the tool sets share an understanding of RF.</span></div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</span></b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif; font-size: small;">Bibliografia: http://mobiledevdesign.com/tutorials/radio_mixing_rf_digital/index1.html</span></b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/mixing-rf-digital-and-analog-circuits.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T18:16:00-07:00">18:16</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=1379954215207265378" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=1379954215207265378" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-45792756258330703442010-07-17T20:27:00.001-04:302010-07-25T08:41:30.053-04:30Satellite Markets Enjoy An Uptick<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Both defense and commercial satellite programs are garnering increased funding, creating opportunities for many microwave products and components.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The term "satellite" conjures many images ranging from television service to cutting-edge military applications like the "mystery" satellites that provide surveillance over troubled areas. With so many automobile drivers equipped with Global Positioning Satellite (GPS) systems, however, satellite applications have become rather commonplace. Yet that does not mean they have lost their innovative edge. Emerging needs continue to open new markets and drive novel applications for RF and microwave satellite technology in the commercial, defense, and space arenas. In doing so, they are providing systems integrators with increased opportunities while giving component makers a chance to support those products.<br />
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Defense has been a steady driver of satellite innovation. In late 2001, for example, the US Air Force awarded Lockheed Martin Space Systems and Northrop Grumman Space Technology a $2.698-billion contract to begin the system development and demonstration (SDD) phase of the Advanced Extremely High Frequency (AEHF) program. In May, Lockheed Martin delivered the first satellite in the AEHF program to Cape Canaveral Air Force Station, Fla., where it is being prepared for a July 30 liftoff aboard an Atlas V launch vehicle. The AEHF system is the successor to the five-satellite Milstar constellation and will provide significantly improved global, highly secure, protected, survivable communications for all warfighters serving US national security. The governments of Canada, The Netherlands, and the United Kingdom participate in the AEHF program as international partners and will have access to the communications capability of AEHF.<br />
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The SDD phase will deploy two AEHF satellites as well as the AEHF mission-control segment, which will support both Milstar and AEHF. Lockheed Martin is developing the ground segment, satellite bus provider, space vehicle integrator, and overall systems integrator and prime contractor. Northrop Grumman provides the payload and associated components (digital processor and RF equipment).<br />
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The Advanced EHF Program is the follow-on to the DoD's Milstar highly secure communication satellite program, which currently has a foursatellite operational constellation. As envisioned by the Pentagon, the AEHF constellation will consist of four crosslinked satellites providing coverage of the Earth from 65 deg. north latitude to 65 deg. south. These satellites will deliver more data-throughput capability and coverage flexibility to regional and global military operations than ever before. A fifth satellite could be used as a spare or launched to provide additional capability to the envisioned constellation.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Compared to the Milstar II communications satellites, the AEHF satellites will provide 10X greater total capacity while offering channel data rates that are 6X higher (Fig. 1). The higher data rates permit transmission of tactical military communications, such as real-time video, battlefield maps, and targeting data. To accomplish this, Advanced EHF adds new higher-data-rate modes to the low- and medium-data-rate modes of Milstar II satellites. The higher-data-rate modes will provide data rates to 8.2 Mb/s for future AEHF Army terminals. Each Advanced EHF satellite employs more than 50 communications channels via multiple, simultaneous downlinks. For global communications, the AEHF system uses inter-satellite crosslinks, eliminating the need to route messages via terrestrial systems.</div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22808/fig_01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="http://mwrf.com/files/30/22808/fig_01.jpg" width="311" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1</div><div style="text-align: center;"><br />
</div><div style="text-align: justify;"> <span style="font-family: Georgia, 'Times New Roman', serif;">An endeavor by the US Navy, called the Mobile User Objective System (MUOS), also leverages Lockheed Martin's expertise. The company is leading a team that includes General Dynamics C4 Systems and Boeing Defense, Space and Security. MUOS, which is a nextgeneration narrowband tactical satellite communications system, will provide the warfighter with the latest mobile technology. Examples include simultaneous voice, video, and data as well as improved service to legacy users of the current Ultra High Frequency Follow-On (UFO) system. Recently, the first MUOS satellite completed passive-intermodulation (PIM), electromagnetic-interference (EMI), and electromagnetic-compatibility (EMC) testing as well as the spacecraft-level baseline integrated system test at Lockheed Martin facilities in Sunnyvale, CA. The first MUOS satellite, along with the associated ground system, is scheduled for on-orbit hand-over to the Navy in 2011.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Among other defense-sponsored satellite projects is the GPS IIIB satellite series, which falls under the US Air Force's next-generation GPS III Space Segment program. Lockheed Martin is working under a $3 billion Development and Production contract to produce up to 12 GPS IIIA satellites with first launch projected for 2014. The contract includes a Capability Insertion Program (CIP) designed to mature technologies and perform rigorous systems engineering for the future IIIB and IIIC increments planned for follow-on procurements.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The Lockheed Martin-led team, which includes ITT and General Dynamics, is progressing in the GPS IIIA Critical Design Review (CDR) phase of the program. It has completed more than 80 percent of the planned CDRs and is well on its path to the overall space vehicle CDR in August—two months ahead of the planned schedule. Successful completion of the space vehicle CDR will allow the team to enter the production phase of the program.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The GPS IIIA satellites promise to deliver significant improvements over current GPS space vehicles, including a new international civil signal (L1C) and increased M-Code anti-jam power with full Earth coverage for military users. For its part, GPS IIIB will enable a cross-linked command and control architecture, allowing these GPS III vehicles to be updated from a single ground station instead of waiting for each satellite to orbit in view of a ground antenna. GPS IIIC will include a high-powered spot beam to deliver greater M-Code power for increased resistance to hostile jamming.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">In addition to improving the satellite technologies themselves, it was recently discovered that military advantages can be gained by leveraging space sensors. Raytheon Co.'s hyperspectral imaging sensor, known as Advanced Responsive Tactically Effective Military Imaging Spectrometer (ARTEMIS), successfully completed its oneyear experimental mission aboard the Air Force Research Laboratory's Tactical Satellite-3. Based on the success of that mission, Raytheon has been notified that the Air Force Space Command will take control of TacSat-3 with the intent to use ARTEMIS in an operational capacity.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Unlike visible imagers, hyperspectral sensors capture light across a wide swath of the EM spectrum, providing heightened spectral detail. That spectral information produces a distinct "signature," which can be compared against the spectral signatures of known objects to rapidly identify potential areas of interest. The ARTEMIS hyperspectral imager combines spectral information with geo-location coordinates in an easy-to-read map. This information is then sent directly to troops on the ground in near real time. Raytheon is discussing opportunities to rapidly deploy additional hyperspectral space sensors.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Some have speculated that defense budgets could suffer due to global economic woes and the public's frustration with the decade-plus range that is said to be required to stabilize the Middle East. Yet according to Euroconsult, government procurement of commercial satellite Earth-observation (EO) data will reach $2.6 billion by 2019—up from only $735 million in 2009. The firm's report, titled "Earth Observation: Defense and Security, World Prospects to 2019," analyzes the mechanisms that defense and security agencies will use to satisfy their image-intelligence (IMINT) requirements over the coming decade. It emphasizes that governments must reconcile their increasingly sophisticated IMINT needs with growing budget constraints. They are therefore exploring cost-effective combinations of solutions, such as the development of dual-use systems, increasing government cooperation to access third-party systems, and purchasing commercial data.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">This increasing demand is being driven by the growing prevalence of commercial high-resolution optical and synthetic aperture radar (SAR) systems, improved image accuracy, and reduced data-delivery times. Commercial data is now suitable for defense intelligence needs, which was not the case in the past. Despite these less expensive alternatives, however, spending for government-owned EO satellites is also expected to see a healthy increase. From 2000-2009, governments in nine nations launched 57 satellites specifically developed for defense applications, representing overall revenues of $12.5 billion for the satellite manufacturing industry worldwide. Over the coming decade, Euroconsult expects manufacturing revenues to grow to $18.3 billion with a marked increase in the number of satellites and average revenue per satellite increasing slightly.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Whether or not the defense segment leverages commercial satellite innovations, the consumer market is certainly driving its own satellite developments. Consumers are now enjoying a vast array of services ranging from satellite television service to GPS navigation systems in their cars. For example, In-Stat recently reported that global demand for digital set-top boxes hit a new high last year with set-top-box shipments increasing by 11 percent. Satellite set-top boxes—the largest market segment—accounted for 48 percent of 2009 global set-topbox unit shipments. Plus, handheld devices like smart phones will offer an increasing array of location-based services (LBSs) going forward. Such services could, for example, alert users to a restaurant's special menu items as they were walking in its vicinity down a city street. Satellite opportunities in the mobile-broadband market also will continue to expand, thanks to the Federal Communications Commission's (FCC's) Spectrum Task Force. It just announced that it will bring 90 MHz of mobile satellite spectrum to market for wireless broadband services.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Iridium Communications, Inc. has long delivered voice and data services for areas that are not served by terrestrial communication networks. Such services are enabled by the firm's constellation of low-earthorbiting (LE) cross-linked satellites. Last month, the company revealed its plans to fund, build, and deploy its next-generation satellite constellation, Iridium NEXT. Iridium has contracted Thales Alenia Space, a joint company between Thales (67 percent) and Finmeccanica (33 percent), for the design and construction of satellites for the Iridium NEXT constellation. This fixed-price contract provides for the construction of 72 operational satellites and in-orbit spares, which were originally planned, in addition to nine ground spares, which provide greater risk mitigation with respect to the new constellation. As a result of the expanded scope of the project, the total cost of Iridium NEXT—including all costs associated with the development, manufacture, and launch of the constellation—is now anticipated to be approximately $2.9 billion. The first satellites are expected to be launched during the first quarter of 2015.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">As an example of the capabilities provided by Iridium, the firm's latest satellite phone, the Iridium 9555, can directly interface with computers running on Windows XP, Vista, and Windows 7 in addition to Mac version 10.4 or later. As a result, it is easier for users to send and receive e-mails as well as exchange computer files through the satellite phone. The Iridium 9555 connects to a laptop with a standard mini- Universal Serial Bus (mini-USB) cable. The phone also offers enhanced short-message-service (SMS) text capabilities, allowing users to send and receive long SMS texts that are up to 1000 characters long.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">In addition to customers in the private sector, Iridium has long provided services to the US Department of Defense and other US and international government agencies. It is now hoping to increase opportunities on the commercial side with the Iridium 9602 data transceiver. Cambridge Consultants —in coordination with Iridium's engineering team—led the design process of the Iridium 9602 short-burst-data (SBD) transceiver. The Iridium 9602 promises to provide greater flexibility for companies looking to integrate satellite communications into a diverse range of remote machine-to-machine (M2M) applications, whether they are fleet management and monitoring, personnel tracking, remote sensor telemetry, or enterprise logistics.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The Iridium 9602 is a single-board unit designed as a black-box transceiver module with all device interfaces controlled by a single multi-pin interface connector in addition to the antenna connector. The 50-Ohm device covers 1616 to 1626.5 MHz. According to Cambridge Consultants, the Iridium 9602 utilizes two customized, application- specific integrated circuits (ASICs). In doing so, it reduces the number of parts from 769 in the previous device to 384. All told, the use of the two ASICs makes the Iridium 9602 approximately 70 percent smaller and 74 percent lighter than its predecessor. More than 90 companies are already working on plans to embed the new model into their next-generation products.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">Asset tracking and monitoring has turned into a huge opportunity for satellite products and services with Iridium just one of many companies targeting this market. By integrating u-blox's UBX-G5010 into its Osprey Personal Tracker, for example, EMS Global Tracking is vowing to provide dependable global positioning and two-way SATCOM to track individuals, assets, and fleets around the world. The UBX-G5010 provides a fine example of the opportunities for microwave companies in such systems. The UBX-G5010 chip requires a minimum of 19 high-frequency components. It includes an integrated low-dropout regulator (LDO) and low-noise amplifier (LNA) as well as crystal resonators and temperature-controlled crystal oscillators (TCXOs). Thanks to an advanced jamming suppression mechanism and innovative RF architecture, the UBX-G5010 vows to ensure maximum GPS and GALILEO performance even in hostile environments and areas with weak signal coverage.</span><br />
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<span style="font-family: Georgia, 'Times New Roman', serif;">The oil and gas sector in particular is experiencing a high growth rate in terms of SATCOM services. Orbit Technologies, for example, just announced that it will supply Telespazio with stabilized marine satellite-communications (SATCOM) systems to be installed on board oil and gas industry installations worldwide. Oil and gas companies increasingly depend on uninterrupted broadband communication for their landbased centers, as the financial cost of interrupted communications can be substantial. The marine SATCOM systems consist of the 1.15-m Ku-band Orsat-G systems and the 2.4-m AL-7108 C-band systems (Fig. 2). They promise to deliver high-speed broadband data transmission/reception capability even in rough seas.</span></div><div style="text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22808/fig_02.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="http://mwrf.com/files/30/22808/fig_02.jpg" width="287" /></a></div><div style="text-align: center;">Figure 2</div><div style="text-align: center;"><br />
</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">These programs and engineering efforts obviously involve some of the biggest names in aerospace and defense. Whether targeted at the defense or commercial segments, however, all of these satellite developments have one thing in mind: They cannot fail. In military applications, failure can result in loss of life. Commercial applications can have lesser implications. Yet the consumer market is fickle in that unsatisfied consumers will show their disdain for a product that does not live up to its promises. To these ends, more and more attention is being given to the issue of satellite interference.</span></div><div style="text-align: justify;"><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">For the microwave companies that sell parts into satellites, interference is a topic that will increasingly be investigated during various design phases. In fact, the interference problem should create even more opportunities in this vast market. In a time when markets are unpredictable and growth is uncertain, a strong market—with military-funded investments—is certainly a welcome prospect.</span> </div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</span></b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://mwrf.com/Articles/Index.cfm?ArticleID=22808&pg=2</span></b></div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/satellite-markets-enjoy-uptick.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T17:56:00-07:00">17:56</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=3909795420242383137" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=3909795420242383137" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-91678816080542045512010-07-17T20:17:00.002-04:302010-07-25T08:41:04.898-04:30X-Parameters Aid MMIC Design<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Models based on X-parameters can provide insights into the linear and nonlinear behavior of key components in wireless systems, including power amplifiers and mixers. </div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The most common method to accurately characterize RF/microwave components under linear conditions has been through the use of S-parameters. However, modeling nonlinear behavior of certain components, such as amplifiers and mixers, is challenging because S-parameters cannot be applied effectively and accurately under large-signal conditions. Approximation techniques have been used for modeling nonlinear behavior—with partial success— by complementing linear S-parameters with nonlinear component specs typically found in datasheets such as 1-dB gain compression point, two-tone third-order intercept point, etc. A much more accurate and comprehensive approach to model nonlinear behavior of RF/microwave components is through the use of X-parameters, which were developed to represent both linear and nonlinear characteristics.<br />
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X-parameters were developed by Agilent Technologies to describe the behavior of both linear and nonlinear components in response to large-signal conditions. X-parameters reduce exactly to Sparameters in the small-signal limit and have the same simple use model as S-parameters. Because they contain information on all the harmonics and intermodulation spectra generated in response to large signals, they are much more powerful than S-parameters and any other nonlinear models available in the industry. X-parameters correctly characterize impedance mismatches and frequency mixing behavior to allow accurate, much faster simulation of cascaded nonlinear Xparameter blocks (e.g., amplifiers and mixers) in design.<br />
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X-parameters can be obtained in one of two ways: generated from a circuit-level design in Agilent's Advanced Design System (ADS) software or measured using the Nonlinear Vector Network Analyzer (NVNA) software running inside the Agilent PNA-X network analyzer. When generated from a circuitlevel design, they offer a simple means of quickly and accurately capturing a component's nonlinear behavior and saving it as transportable RF intellectual property (IP) models that can be used for circuit or system designs. X-parameter models can be used to share design performance without revealing design topology.<br />
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Agilent has published the equations underlying the X-parameter theory and the Xparameter files are in an open, non-encrypted format. Agilent has taken these steps to enable broad industry adoption and to encourage others to join in the development of the technology. To gain a better understanding of how circuit-level designers can easily generate fast and accurate, transportable X-parameter models, consider the example of a two-stage MMIC power amplifier (PA) designed in ADS for 3GPP Long Term Evolution (LTE) applications (Fig. 1). The goal is to generate a 50-O X-parameter model of the component. The same process outlined in this article can be used to generate accurate X-parameter models for mixers and other nonlinear components.</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22811/fig_01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="260" src="http://mwrf.com/files/30/22811/fig_01.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
The first step in creating an Xparameter model is to generate the component's X-parameters. In ADS, this can be done by inserting the circuit-level design into a schematic page, attaching it to an X-parameter source, load, and bias, and clicking the "Simulate" button. In seconds, an X-parameter model is generated that can be e-mailed to the system integrator for immediate use.<br />
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To validate the accuracy of the generated model and compare it with the actual circuit-level MMIC PA, both the X-parameter model and MMIC PA design are inserted into a nonlinear simulation setup and nonlinear simulation and analysis are performed. Figure 2 shows the magnitude and phase of the fundamental, as well as the second and third harmonics of both results. This comparison clearly demonstrates that the X-parameter model has the same accuracy as that of the circuit level design and, therefore, a system integrator can insert the MMIC PA model into an LTE uplink transmit system design and use it as if it were the actual circuit-level PA.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22811/fig_02.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="353" src="http://mwrf.com/files/30/22811/fig_02.jpg" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"> Figure2</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
The MMIC PA model was generated assuming a 50-O load and works well within a system matched to 50 O, accurate within about a 2.0:1 VSWR. If non-50-O modules are used in the system, a designer must be able to sweep the entire load over the Smith chart and generate a model that would work with any load impedance, not just in the 50-O region.<br />
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Figure 3 helps show the importance of load-dependent models. It shows the MMIC PA connected to a duplexer and antenna. If the load impedance on the PA is unknown, an impedance mismatch in magnitude and phase could result at both fundamental and harmonic frequencies. The only way to accurately predict the behavior of the PA in the system under any load impedance is a load-dependent X-parameter model that contains accurate information on the magnitude and phase of the fundamental frequency and all the harmonics.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22811/fig_03.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="197" src="http://mwrf.com/files/30/22811/fig_03.jpg" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 3</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
An example of a design problem would be where the gamma load of the second harmonic on the PA creates distortion that degrades cell phone performance and possibly even PA efficiency and shortens battery life. To correct the problem, the exact magnitude and phase content of the second harmonic tone must be known in order to filter the unwanted harmonic signals. Unlike other available industry models that capture nonlinear behavior only on the fundamental frequency, the X-parameter model accurately captures the behavior on all the harmonics. By providing complete information on the magnitude and phase of the second harmonics, the model allows designers to filter out this unwanted second harmonic and improve the overall design and performance of the cell phone.<br />
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Generating a load-dependent model is simple and follows the process previously outlined, with the exception that a load sweep must be added to the design. A designer simply inserts the circuit-level PA design into a template in ADS, clicks the Simulate button and a model is automatically generated. This newly generated load-dependent X-parameter model is fully IP-protected and is automatically stored in the project's data set folder and can be immediately shared with the system integrator for accurate higher up simulation and tradeoff analysis on matched or mismatched cascaded modules.<br />
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Figure 4 shows simulation results from both the load-dependent model and the circuit-level PA with a gamma of 0.7 and phase between -180 and +180 deg. With these criteria, the generated model is accurate with any load impedance within 70 percent of the Smith chart. The overlaid power and power-added-efficiency (PAE) contours of the model and the circuit level PA demonstrate the accuracy of the X-parameter model to the circuitlevel PA.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22811/fig_04.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="184" src="http://mwrf.com/files/30/22811/fig_04.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 4</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">To further evaluate the X-parameter model under mismatch conditions, it will be used to represent two cascaded PAs with mismatch between them. Individually, the output return loss of the PA (S22) is excellent when it is driven hard. But if the PA is driven with a small signal, S22 naturally degrades and moves away from 50 O because the output FET capacitance and resistance change as a function of drive level. Cascading two of these PAs will therefore result in mismatch between them. The source impedance of the second PA is no longer 50 O. Rather, it is now the degraded S22 of the first PA since it is driven with a small signal. This scenario offers a good test case for the model. </div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Figure 5 shows the simulation results for the cascaded PAs and the cascaded models. Again, the overlaid results demonstrate the high accuracy of the model under any load impedance and with cascaded mismatch conditions.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://mwrf.com/files/30/22811/fig_05.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="272" src="http://mwrf.com/files/30/22811/fig_05.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"> Figure 5</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Bibliografia: http://mwrf.com/Article/ArticleID/22811/22811.html</b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/x-parameters-aid-mmic-design.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T17:46:00-07:00">17:46</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=2022716294341963497" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=2022716294341963497" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-70627904108817629702010-07-17T19:59:00.002-04:302010-07-25T08:40:39.465-04:30RFIC (radio frequency integrated circuit)<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Los RFIC (del inglés radio frequency integrated circuit) son circuitos integrados que trabajan en el rango de ondas de radiofrecuencia.<br />
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La electrónica actual tiene una fuerte tendencia al empleo de las tecnologías inalámbricas, en las cuales se conjuga toda la potencialidad del procesado digital y analógico, para altas frecuencias, en un mismo sistema. Estos sistemas integrados requieren bajo coste, bajo consumo, altas prestaciones y tamaño reducido, en donde el papel que juega la tecnología CMOS es vital para la expansión de los sistemas inalámbricos.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/8/8d/CMOS_LNA.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="286" src="http://upload.wikimedia.org/wikipedia/commons/8/8d/CMOS_LNA.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>Historia</b></span><br />
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En los últimos años la tecnología CMOS ha evolucionado notablemente logrando mejoras en los niveles de integración y velocidad de proceso. Esto aunado a su bajo coste ha permitido la integración de procesadores digitales junto con el procesado analógico de la señal, dando lugar a la implementación de circuitos integrados de modo mixto. Por su parte, los circuitos integrados de Radio Frecuencia (RF) han sufrido un explosivo crecimiento por su extensa aplicación en sistemas de comunicación y equipos inalámbricos. Con respecto a los problemas tecnológicos, que se derivan de la implementación de estos sistemas en tecnología CMOS, cabe destacar el trabajo realizado por Thomas H. Lee. A él se le deben numerosas contribuciones teóricas de tecnología y diseño en este campo.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b>Circuitos Activos y Pasivos de Microondas</b></span><br />
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Los circuitos de microondas están divididos en dos grandes grupos: circuitos activos y circuitos pasivos. Los circuitos pasivos no agregan potencia a la señal que reciben, mientras que los activos sí que pueden agregarla. Los circuitos pasivos incluyen desde elementos discretos como resistencias, inductancias y capacitancias hasta circuitos mas complejos, tales como: Filtros, divisores,combinadores, duplexores, circuladores, atenuadores, líneas de transmisión... Entre los circuitos que pueden ser tanto activos como pasivos, están las antenas, multiplexores, mezcladores... Dentro de los circuitos activos se encuentran los RFICs, diodos, MMICs, receptores, moduladores, osciladores...</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><h2 style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span class="mw-headline" id="La_clave_la_integraci.C3.B3n">La clave la integración</span></h2><div></div><div class="thumb tright" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><div class="thumbinner" style="width: 302px;"><div class="thumbcaption"></div></div></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Los sistemas de comunicación inalámbricas transmiten las señales a frecuencias de unos pocos GHz (usualmente entre 1 GHz y 3 GHz); en estas bandas operan sistemas y servicios cuyo impacto es significativo (Bluetooth, 2,4 GHz; UMTS, GPS, DECT, etc). </div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">La demanda actual de estos equipos se ha satisfecho mediante sistemas MCMs, o fundamentalmente, con circuitos, tanto integrados como discretos montados sobre PCBs, basados ambos en tecnologías III-V maduras. El principal problema del uso de estos circuitos es el alto coste y el bajo volumen de producción, es muy limitado. Sin embargo, las necesidades del mercado exigen componentes de radiofrecuencia (RF) pequeños, baratos, de bajo consumo y producción masiva. De modo que los grupos de investigación y, en especial, las empresas de diseño y fabricación de sistemas para RF enfocan sus líneas de investigación para desarrollar circuitos integrados estándar de silicio: CMOS y BiCMOS. Por tanto, los dispositivos activos en estas tecnologías alcanzan las frecuencias requeridas con unas dimensiones muy pequeñas; pero surge un nuevo problema, no se dispone de inductores de calidad.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Esta carencia anteriormente citada es muy restrictiva, pues implica la adaptación de las redes a altas frecuencias mientras que no es necesario, si se está trabajando con bajas frecuencias (por ejemplo, la utilización de circuitos de adaptación de impedancia compleja). Los inductores de calidad, son componentes pasivos y necesarios para muchas otras funciones, como la polarización de transistores en amplificadores de bajo ruido (LNA) o la implementación de tanques LC (circuitos resonadores sintonizados) en osciladores. Otros componentes además de los inductores de calidad, son los varactores integrados que amplíen el rango de valores de la capacitancia sin que ello exija una gran cantidad de área para la integración.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">El escalado de la tecnología CMOS (>65nm), ha permitido llegar a la integración en un solo chip de gran capacidad de procesado, comunicaciones inalámbricas (wifi, bluetooth), memoria, video, circuitos de RF, audio. Estos RFIC nos permiten disponer de terminales móviles que integran en un solo chip tecnología cuatribanda, cámara de fotos, navegador de internet, reproductor mp3, reproductor de video, agenda, etc </div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
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</div><div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/4/4d/Layout_de_una_bobina_espiral_cuadrada_simple.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="196" src="http://upload.wikimedia.org/wikipedia/commons/4/4d/Layout_de_una_bobina_espiral_cuadrada_simple.JPG" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Bluetooth es un estandar de conectividad wireless que provee comunicaciones de voz y datos de bajo coste para enlazar teléfonos móviles PDA, PC, cámaras digitales y otros dispositivos portátiles. Está tecnología trabaja a 2.4 GHz. Los dispositivos Bluetooth operan en tres clases de potencia. La clase 2 opera a 0 dBm, la clase 2 opera a 4 dBm y la clase 1 opera a 20 dBm. Todas ellas transmite datos a 1 Mbps y la última generación oscila entre 2 y 12 Mbps</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Por lo tanto estos dispositivos deben ser capaces de controlar la potencia desde 20 dBm hasta 0 dBm, Bluetooth habilita este control de potencia optimizándola con LMP (Link Manager Protocol). Consiste en medir la señal recibida (RSSI) y reportando si la señal debe ser amplificada o no. Bluetooth además es considerado un estandar de bajo coste, y lo consigue gracias a la tecnología CMOS. CMOS es usado en esta tecnología como amplificadores de potencia, a continuación se muestra un esquema de un amplificador de este tipo</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"> <span class="mw-headline" id="Problemas_de_dise.C3.B1o"> </span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b><span class="mw-headline" id="Problemas_de_dise.C3.B1o">Problemas de diseño</span></b></span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span class="mw-headline" id="Problemas_de_dise.C3.B1o"> La integración de la sección digital y de RF sobre un mismo sustrato es un tema de gran interés en la actualidad por las diferentes dificultades que ello conlleva. La problemática de la integración de estas dos secciones tan diferentes repercute en todos los niveles de abstracción y flujos de diseño, desde el desarrollo de la arquitectura, particionado, simulación, pruebas, elección de estándares, normativas, algoritmos, protocolos de comunicación, pasando por aspectos de simulación (CAD y modelado) para la planificación y coordinación de flujos de diseño (en sus diferentes niveles de abstracción), todos estos aspectos enmarcados y delimitados por el desarrollo de la tecnología actual y futura. Por lo tanto, a pesar de las ventajas, es innegable que la tecnología CMOS sufre de una serie de limitaciones, de entre las cuales se destacan los problemas referentes a la integridad de la señal. De entre estos problemas, el ruido de conmutación puede ser considerado un factor crítico en el diseño de Circuitos Integrados. La actividad eléctrica de los nodos digitales se acopla desde la red de distribución de energía al sustrato, implicando la transmisión de ruido a puntos sensibles de las secciones analógicas o de radiofrecuencia (RF), lo cual degrada notablemente sus prestaciones</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: large;"><b><span class="mw-headline" id="Problemas_de_dise.C3.B1o">Aplicaciones</span></b></span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span class="mw-headline" id="Problemas_de_dise.C3.B1o"> </span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span class="mw-headline" id="Problemas_de_dise.C3.B1o">Las principales aplicaciones de los circuitos integrados de radiofrecuencia son los productos para comunicaciones inalámbricas, como por ejemplo, teléfonos móviles y PCS (servicio de comunicaciones personales: conjunto de tecnologías digitales celulares), estaciones base, redes de área local inalámbricas y módems para televisión cable.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span class="mw-headline" id="Problemas_de_dise.C3.B1o"><br />
</span></div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/0/02/RFIC_telefonia.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="107" src="http://upload.wikimedia.org/wikipedia/commons/0/02/RFIC_telefonia.JPG" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b><span class="mw-headline" id="Problemas_de_dise.C3.B1o">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</span></b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b><span class="mw-headline" id="Problemas_de_dise.C3.B1o">Bibliografia: http://es.wikipedia.org/wiki/RFIC</span></b></div><span class="mw-headline" id="Problemas_de_dise.C3.B1o"><br />
</span> </div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/rfic-radio-frequency-integrated-circuit.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T17:28:00-07:00">17:28</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=2267993852935552836" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=2267993852935552836" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-50018175166001754432010-07-17T19:29:00.002-04:302010-07-25T08:40:13.306-04:30Passives for RF design<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">(Passives for RF Design) Designers can choose from fully integrated systems or fully discrete solutions with their associated pros and cons. Both thin film and PMC are rapidly developing technologies, and a number of new devices will soon be emerging. The PMC process is ideal for integration of the passive content of the RF circuit to optimize PA or LNA performance for a given application.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Radio continues to be one of the most powerful technology drivers in microelectronics with many evolutionary changes taking place in the last few years. Consumer and mission-critical applications require solutions that are smaller, increase functionality and reliability, and improve signal clarity, while attaining lower power consumption.<br />
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To achieve this, almost all modern radios now use digital modulation schemes instead of standard analog. This also fits with the trend of higher frequencies to make use of the wider bandwidth required for these applications. The higher-frequency designs also drive to smaller physical layout because the shorter wavelengths can be accommodated in much smaller packages (i.e., the wavelength at 5.8 GHz is nearly 6.5 times smaller than at 900 MHz).<br />
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Although radio design continues to evolve with increasing complexity and need for security, the actual radio block diagram has remained virtually unchanged.<br />
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Figure 1 is a block diagram of a dual-conversion super-heterodyne transceiver, one of the most common radio design schemes used today. However, the direct-conversion (zero intermediate frequency) receiver is gaining momentum. The direct-conversion receiver has a single mixing stage that converts the received signal directly to baseband and reduces the cost considerably — at the expense of performance.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg52wdvEO3_hbyy_qwXsrAr9AL63rHaGvlMLMfgdQIZvYEJ3CvHc-UMQyaeVNGdfQrD_4gN2nfgr6q2WXJVIEAythvaGGuHRMPoDLO-WvUJPvBedBlt_alE3cE-B7iRB197bmTXusO8Ggc/s1600/cosa.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg52wdvEO3_hbyy_qwXsrAr9AL63rHaGvlMLMfgdQIZvYEJ3CvHc-UMQyaeVNGdfQrD_4gN2nfgr6q2WXJVIEAythvaGGuHRMPoDLO-WvUJPvBedBlt_alE3cE-B7iRB197bmTXusO8Ggc/s320/cosa.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1. Basic super heterodyning transceiver.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
The basic radio consists of several key components, and each has a specific job in the chain: antenna, switch, low-noise amplifier (LNA), filter, mixer, oscillator, modulator/demodulator. As the applications have evolved, so has the component technology that has enabled major downsizing of these elements to take place.<br />
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Early radio designs were necessarily based on discrete passive components designed for high-frequency performance. These use low-loss, high-frequency dielectrics (NP0 ceramic, porcelain or glass), but require precious metal electrode systems that can withstand the high firing temperatures associated with ceramic material processing and still provide good conductivity. These devices remain a suitable solution for high-power RF applications but are nearing the limit of downsizing for microcircuit applications.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
<span style="font-size: large;"><b>LTCC technology</b></span><br />
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The next stage of evolution came with low-temperature co-fired ceramic (LTCC) technology. This technology enables integration of passive components within compact modules and can provide a platform for actives. This integrated technology does yield small size but requires careful design discipline to achieve repeatable characteristics. LTCC is essentially a "wet" or tape process technology: Material is screened in place, building up the device layers, while the lower temperature manufacturing process enables the use of more standard conductive metals such as copper for internal electrodes and contacts. Plated-through vias are used for interlayer interconnection, and the electrical conductors can be configured in plates (capacitors) or spirals (to make efficient inductors). Different low-temperature ceramic materials with a variety of characteristics are available, including high-capacitance density dielectrics, but these yield high-dielectric constant at the expense of tighter temperature and voltage coefficients that characterize the high-temperature ceramic types.<br />
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This type of lay-down process also has wider process tolerances (from the capability of the wet system to the variability of post-firing shrinkage) with interconnect line widths limited to ~150 microns. Table 1 gives comparative data for key characteristics. The technology is applicable to the passive and active modules, such as power amplifiers (PAs), RF switches, and RF front-ends by integrated capacitors, resistors, and inductors in a small area. The process results in a mechanically strong and compact structure but does limit the materials available for RF component design.<br />
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One challenge facing designers working with LTCC is the ability to characterize the RF properties of the complex internal structures that lack electrical models. Most embedded components, especially spiral inductors and parallel plate capacitors, suffer from significant parasitic coupling due to their large area and proximity to other structures or to ground planes.<br />
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It follows that LTCC modules are more suited to application-specific designs in high-volume platforms, as varying the design for different configurations becomes more problematic as their complexity increases. This technology also benefits from economies of scale — once upfront costs for custom design and characterization have been met, the process itself can support low-cost manufacturing — but it also limits any future revisions and changes without a module redesign.<br />
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Because LTCC technology in itself is not always the optimum performance solution, there has been an increased interest in new integrated devices that have evolved from discrete solutions based on thin film technology.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
<span style="font-size: large;"><b>Thin film solutions</b></span><br />
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Thin film technology, as a first step, goes back to a discrete format. The key difference with this technology is that it is based on photolithography and plasma-enhanced chemical vapor deposition (PECVD) processing. The photolithography gives extremely precise geometry, while the low-temperature PECVD process combines the benefits of high conductivity conductors with the use of highly stable dielectrics (e.g., SiO2) deposited on a stable alumina base. The technology also allows downsizing to 0201 size and further integration. The most basic element is the thin-film capacitor as shown in Figure 2.</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4NgNQ7z0ONfCMhvF_fYQRLW2MBKEQxUAbH39JXPgvUpb9DDygX4mcp5yNYuJHCrPsk22vsi6_UV6z5mM7i067t2JH_R7g9VqAz__205Tn2tGHW7LvV_BkZ04ajuDT1K3y0gSSnwerAlo/s1600/cosa1.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4NgNQ7z0ONfCMhvF_fYQRLW2MBKEQxUAbH39JXPgvUpb9DDygX4mcp5yNYuJHCrPsk22vsi6_UV6z5mM7i067t2JH_R7g9VqAz__205Tn2tGHW7LvV_BkZ04ajuDT1K3y0gSSnwerAlo/s320/cosa1.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 2. Thin-film capacitor structure.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The system above is characterized by stable dielectric, single-layer construction, which eliminates harmonics, is readily modeled and is reproducible. Designs breadboarded on the bench will be precisely reproduced in mass production at the CEM, month to month and year to year. Because the parts are discrete circuit elements, there are no up-front design costs and full design flexibility is maintained throughout the program lifetime. Ultra-stable dielectrics usually have a trade off: low dielectric constant. But thin film is capable of far thinner dielectric films (~1 µm) compared to LTCC (50 µm to 250 µm), which results in a higher cap yield per mm2. The conductors used for the electrodes also have lower resistivity (~1 m▸/mm2) than their LTCC counterparts (10 - 20 m▸/mm2), giving greater RF power-handling capability. Because of their precision, these devices can be used in conjunction with LTCC packages, while any given LTCC module will have limited design flexibility. The small size and termination compatibility of discrete thin film devices means that they can be used to fine-tune an application or modification or tuned last-minute for Federal Communications Commission (FCC) compliance.<br />
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Figure 3 shows how these components are typically configured in a standard radio application.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgS3TUOaQ5k0yR1H1eJAhp23DdSGVB8Cg9UIhJxopPrH72FZN74z29Wn4C_5dcOy99SCkihvsrPE7xjGSJ6ljOkYctUzFIiMtI908GC67SI1BCXsw6qfaw31k1IMSQ15ZgWILcVnssoHTc/s1600/cosa2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgS3TUOaQ5k0yR1H1eJAhp23DdSGVB8Cg9UIhJxopPrH72FZN74z29Wn4C_5dcOy99SCkihvsrPE7xjGSJ6ljOkYctUzFIiMtI908GC67SI1BCXsw6qfaw31k1IMSQ15ZgWILcVnssoHTc/s400/cosa2.JPG" width="400" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 3. Key design areas for thin film technology.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
The LNA is one of the more critical sections in the receiver circuitry. To maximize the performance, it is essential to have stable biasing and accurate impedance matching. Thin film provides discrete capacitors and inductors with high Q, low equivalent series resistance (ESR), and accurate capacitance values (±.01 pf) and inductance values (±.1 nH).<br />
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By using this technology, a low-noise amplifier (LNA) can have a more accurate match over temperature and greater repeatability from board to board compared to both traditional discrete devices and wider-tolerance LTCC.<br />
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Figure 4a shows the deviation in S11 when comparing NP0 multilayer ceramic capacitor (MLC) vs. thin film capacitors. Notice that the thin-film capacitor response tracks with no variation between parts. This demonstrates exactly how precise the thin-film process can be from capacitor to capacitor and from batch to batch. This not only improves the quality of the LNA, it can actually improve the yield in manufacturing by eliminating the fine-tuning of circuits in production. Figure 4b shows the response at higher frequencies. Being single-layer devices, thin film shows no harmonic resonances.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBPtmoz_hjBt62HZhUw5tNYYobHwYae4KhnsGxpXTHIDuj_oGt6Ybw-YSxnRLVCRzrbxirv-BZxppsgfe-5foYeCN6vBpafxCp1tzLbLqRR5Imo016DJiJyqpnlRGZ7tnk6lueCZnbB3o/s1600/cosa3.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBPtmoz_hjBt62HZhUw5tNYYobHwYae4KhnsGxpXTHIDuj_oGt6Ybw-YSxnRLVCRzrbxirv-BZxppsgfe-5foYeCN6vBpafxCp1tzLbLqRR5Imo016DJiJyqpnlRGZ7tnk6lueCZnbB3o/s320/cosa3.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 4. Thin film vs NP0 MLC ceramic.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
The same components can be used to accomplish the critical matching of the input and output of a power amplifier. By using low-loss, thin-film capacitors and inductors, more power can be sent to the amplifier transferred to the antenna. This results in improved performance and increased efficiency of the power amplifier, as well as improved temperature performance.<br />
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Antenna matching is also a critical design issue. The available real estate for the antenna is continually decreasing, which generally leads to a non-ideal form-factor design. This situation will almost always require an impedance matching circuit for the antenna. Thin film capacitors and inductors are ideal for this application, providing an accurate match of impedance to the antenna to maximize energy transfer under all conditions to minimize losses from the PA or to the LNA.<br />
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Beyond high-accuracy microminiature capacitors and inductors, thin-film PECVD technology also lends itself to integration. By combining both a capacitor and inductor element on the substrate, an inductor and capacitor (LC) low-pass filter (LPF) can be formed, as shown in Figure 5. These can be made in the same small form factors (0402 and up) and so use little board space while saving cost through component count reduction. These thin-film filters provide high out-of-band attenuation (greater than 30 dB) while maintaining the lowest insertion loss available to the RF designer (less than 0.3 dB). They can also be used to isolate the frequency of interest on the output of the mixer after conversion. The filters must be internally matched to 50 ▸ in order to achieve specified performance.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmMHm5bVntNANxAnyEJznID597gzmgd11qwa4Jd1tvS_vOHvXnFEf0XHV6Lo7Ez-9ONM-TQ_pnR0GIcZfupXV00FwALEfK9TCJoJmspN1mz99ClMukBasHHI8ou5bbOM2ECOdgaKMk5ac/s1600/cosas4.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmMHm5bVntNANxAnyEJznID597gzmgd11qwa4Jd1tvS_vOHvXnFEf0XHV6Lo7Ez-9ONM-TQ_pnR0GIcZfupXV00FwALEfK9TCJoJmspN1mz99ClMukBasHHI8ou5bbOM2ECOdgaKMk5ac/s320/cosas4.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 5. Thin film LPF and response for a 915 MHz LPF.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A directional coupler is a device that samples an RF/microwave signal while minimizing loss to the signal. Thin-film devices, based on back-to-back inductors, produce high-directivity, low-insertion-loss directional couplers. These couplers offer the highest amount of directivity found on the market today, in small package sizes down to 0402. In the diagram in Figure 6, the coupler is being used to sample the output and send the sample to a gain control circuit for the power amplifier. As with the LPF, the couplers are also capable of handling up to 3 W continuous power.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh59v2uLd5Tg-jYcerQ_fhJzCZYnoZjDtR7WnXD0ws3E8xKU17M517pgIf-ooNjyKBnjhvyrl6XwL5eeNJXjRk153H_FP5v82bDBTtIb_l48Aa0lMgzNydXpXkXWsDJOmombzUa8GRHHbk/s1600/cosas5.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh59v2uLd5Tg-jYcerQ_fhJzCZYnoZjDtR7WnXD0ws3E8xKU17M517pgIf-ooNjyKBnjhvyrl6XwL5eeNJXjRk153H_FP5v82bDBTtIb_l48Aa0lMgzNydXpXkXWsDJOmombzUa8GRHHbk/s320/cosas5.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 6. Directional coupler.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
Directional couplers work from the principal of field coupling. The electric field produced by a transmission line in series with the signal is coupled onto an adjacent conductor through the air or dielectric medium. Coupler elements can be included within LTCC modules. The technology allows lumped elements, rather than coupled lines, to produce directional couplers to 10 dB. However, thin-film technology has a number of advantages in this area. The finer line widths maximize the coupling coefficient, making available hybrid couplers to 3 dB in 0603 size.<br />
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This coupler, with port configuration shown in Figure 7, is designed to couple 3 dB of power to another channel, with the addition of a 90 ° phase shift to the signal. This can be useful in designs using an in-phase and quadrature (I/Q) architecture where the channels are 90 ° out of phase. By using a hybrid coupler on the output of the oscillator, the local oscillator (LO) can be generated for both I and Q sections. It can also be instrumental when using two amplifiers to improve the linearity by splitting the power between the two circuits and then recombining after amplification. This reduces harmonic emissions, improves efficiency and increases gain from an amplifier.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWz3GPGwrSFo5HwkllM6W9vIDRcWo5voojJHU_uPqHV3eD8XIJJ09IAxWdxO3agzBF3LQVr__j5xhNpzIQG_t1AfLhixuxf_UXE5KNl7nwMoVk0_d15Q6bmo-VBn-gIu404nXW6BL4nq8/s1600/cosas6.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWz3GPGwrSFo5HwkllM6W9vIDRcWo5voojJHU_uPqHV3eD8XIJJ09IAxWdxO3agzBF3LQVr__j5xhNpzIQG_t1AfLhixuxf_UXE5KNl7nwMoVk0_d15Q6bmo-VBn-gIu404nXW6BL4nq8/s320/cosas6.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 7. Hybrid couplers used to improve linearity.</div><div style="text-align: justify;"><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The latest stage in evolution is passive microcircuits (PMC). PMC goes to the next level of passive integration. Its key advantages are that it retains the minimum line width capability and line width precision of thin film, but increases the maximum stacking layers capability. This can be used for increased capacitor and resistor density per mm2 and added turn capability in inductor elements. Table 1 gives the prime characteristics for these materials.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The PMC process is ideal for integration of the passive content of the RF circuit to optimize PA or LNA performance for a given application. As with all integration, the higher the complexity, the more single-application specific the device.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">In summary, designers have choices at the outset of the product cycle to choose from full integrated systems to full discrete solutions with their associated pros and cons. Both thin film and PMC are rapidly developing technologies, and a number of new devices are guaranteed to be emerging during the next few quarters.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="text-align: justify;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://rfdesign.com/mag/508RFDF2.pdf</span></b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/passives-for-rf-design.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T16:58:00-07:00">16:58</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=9145078855319000118" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=9145078855319000118" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-32746506723912538342010-07-17T19:02:00.002-04:302010-07-25T08:39:46.703-04:30Overcoming the RF challenges of multiband mobile handset design<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Demands on components in the RF signal chain of a mobile handset increase with the number of bandwidths and modes, especially for the antenna and its switch. The integration capabilities of RF CMOS devices solve many of these issues while maintaining peak performance.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">CMOS has long been regarded as the technology of choice for integration, particularly in high-volume applications where cost is a major driver. During the last few years, advances in CMOS technology have led to its use in analog devices, and then into the intermediate frequency (IF) and radio frequency (RF) domains that were once dominated by BiCMOS and GaAs. As the industry drives forward with multiband applications, these developments have come not a moment too soon.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The bottom line is that the RF signal path in a mobile handset has become extremely crowded. The complexity of cellular phones has grown at a rapid pace, moving from dual-band, to tri-band, and now quad-band. In addition, these phones also need to handle a variety of signals for peripheral radios, such as Bluetooth, Wi-Fi, and GPS. This trend is expected to continue as WiMAX and LTE (4G) capabilities are added. In a mobile handset, the antenna switch is the gatekeeper that controls antenna access for all of the radio signals. Currently, designers are specifying new single-pole, 9-throw (SP9T) switches, and we can reasonably expect that SP10T is not far away.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b><span style="font-size: large;">RF challenges</span></b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
Handsets now being developed incorporate tri-band WCDMA and quad-band EDGE platforms, an architecture that demands at least seven radios in a single handset. Most likely, the market will standardize on at least seven bands, with room for an eighth (for LTE). Regardless, complexity will continue to rise due to the increased popularity of peripheral radios and functions that also need access to the antenna.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">All of this has greatly complicated the RF front-end by more than tripling the number of high-power signal paths engineered in today's quad-band EDGE handsets. By its nature, a multiband handset must handle numerous RF paths that all operate on different bandwidths. Yet, they all need to access the same antenna. The most effi cient approach is to path all of the signals through a single RF switch. For switch manufacturers, this has meant a corresponding evolution from single-pole 4-throw (SP4T), to SP7T, to now SP9T confi gurations in order to handle the increased number of signals. Increased functionality also impacts the antenna, which must effectively radiate from 800 MHz to 2200 MHz from a tiny footprint. Antenna designers are addressing these issues by taking advantage of performance-enhancing matching, switching, and lumped tuning elements. Ultimately, though, it is the RF switch that must be capable of switching up to nine paths or more of high-power RF signals with low insertion loss, high isolation, and exceptional linearity. Next-generation designs require to/from fi lter banks, and, as a result, the burden on the switch element is high. In terms of specifi cations, new applications tend to require very low insertion loss due to the signal going through multiple switch paths; very high linearity due to a WCDMA platform; very high isolation for critical paths; and a small, effective switch solution for independent (yet simultaneous) signal paths with up to 14 control states. In a mobile handset, RF designers are typically responsible for the antenna switch module (ASM), front-end module (FEM), and the transmit module. The ASM typically includes a switch, decoder, power amplifi er (PA) low-pass fi lters, ESD circuitry, and a voltage generator.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiofNwFDP9K41hkHCp0oFqjtZq4XbQ8ZitMZX6caRLOittmF1Eb0S-mOmHU8RKS-8GUyZLiksUNHzVmL-br7QTRf1uHjGDF0SOpjOh0wlmmtQHD2r0ACa30HnL6Irkjw5phW5faxOvPm7s/s1600/Dibujo.bmp" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiofNwFDP9K41hkHCp0oFqjtZq4XbQ8ZitMZX6caRLOittmF1Eb0S-mOmHU8RKS-8GUyZLiksUNHzVmL-br7QTRf1uHjGDF0SOpjOh0wlmmtQHD2r0ACa30HnL6Irkjw5phW5faxOvPm7s/s320/Dibujo.bmp" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"> Figure 1. Next-generation mobile handset design must handle a multitude of receive and transmit signal paths.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A multimode, multiband mobile handset generally uses a single PA module to handle all of the quad-band GSM/EDGE signals. In contrast, each WCDMA signal requires its own individual PA. Figure 1 shows a next-generation mobile handset design. The orange area shows the additional PAs and filters that are required to handle the multitude of receive (Rx) and transmit (Tx) signal paths.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"> A quad-band GSM handset with one WCDMA band requires at least a single-pole, 6-throw (SP6T) switch to manage all of the signal paths. Designers could use a diplexer and two SP3Ts (which is a popular GaAs configuration), but this results in higher insertion loss than when using a single SP6T switch. In all of these designs, a multiband scenario means significant architectural, performance, and cost challenges. And, any design trade offs in a multiband phone still require the handset to meet or exceed the performance levels of all the standards supported.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"><span style="font-size: large;"><b>Insertion loss</b></span></div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Insertion loss is important in multiband designs because it directly impacts the effective power-added effi ciency (PAE) of the PA. GSM PAs are typically run in saturation at up to 3 W, with an average PAE of 55%. The PA is responsible for half of the total current drain in the handset, so any deterioration of efficiency has a direct impact on battery life. Maintaining the PA's PAE, then, needs to be a high priority. Early multiband WCDMA/GSM handsets featured separate signal chains for WCDMA and GSM that were then pathed to separate antennas. While this worked for prototypes and fi rst-generation designs, market pressures required a more cost-effective, spacesaving approach. Clearly, the industry needed integrated ASMs that handled seven or more signals.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Initially, SP7T switches were used to support handset architecture with one WCDMA and four GSM bands. Later, designs such as the PE42693, a monolithic SP9T, were developed on UltraCMOS process technology. Figure 2 shows insertion loss over frequency for this switch in terms of multiple transceiver (TRx), Tx, and Rx signals. This level of performance is necessary to ensure effi cient RF front-end designs. The SP9T switch is one of the latest advancements in switch architectures. It can be confi gured to handle multiple bands of WCDMA, GSM, and peripheral radios. The switch in Figure 1, for example, is handling three bands of WCDMA, with paths to duplexers and three PA modules. The switch also handles quad-band GSM/EDGE, which has a single PA module associated with it. In effect, this device has to route fi ve highpower signals through a single switch that is controlled by a simple decoder.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_ufRiPbZy8OlihXBK0VZS4LVOwAdXdk7Gn8rd9OTZN6OoMZrGuUrKe5e7zFJGdfQXLAYjCtmFgEywX-bmAsnY1g8hlCEmZ9MAekPPMwhpdxQBrQ7daQj1HpKkHVgktwRXdbggW2WwB7g/s1600/1.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_ufRiPbZy8OlihXBK0VZS4LVOwAdXdk7Gn8rd9OTZN6OoMZrGuUrKe5e7zFJGdfQXLAYjCtmFgEywX-bmAsnY1g8hlCEmZ9MAekPPMwhpdxQBrQ7daQj1HpKkHVgktwRXdbggW2WwB7g/s320/1.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 2. The PE42693 SP9T from Peregrine demonstrates TRx insertion loss of 0.70 dB at 850 MHz WCDMA.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
<span style="font-size: large;"><b>Linearity</b></span> </div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Adding more bands to the handset has greatly increased the technical requirements of the switch, and the linearity and harmonic requirements of WCDMA have put a large strain on the performance. For instance, a switch is now generally agreed to need a third-order intercept point (IP3) of better than +65 dBm. In previous GSM-only designs, there was no comparable linearity requirement. The increased front-end complexity of newer designs makes this high level of linearity extremely difficult to achieve for an active device on any manufacturing process. However, by leveraging the linearity<br />
advantages of the UltraCMOS process, the monolithic PE42693 SP9T in Figure 1 is able to maintain the +68 dBm IP3 of its SP7T predecessor with third-order intermodulation distortion (IMD3) performance that surpasses the industry specification of -105 dBm. This level of IMD3 performance<br />
reduces the potential for interference within the mobile handset's radio.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"><b><span style="font-size: large;">Isolation</span></b></div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">As the number of signal paths in the handset has grown, so has the need for better isolation. The number of input/outputs (I/Os) in an ASM dictates the level of isolation required. For instance, a gallium arsenide (GaAs) SP9T typically requires 18 control lines. In addition to making it challenging to route all of these lines in and out of a singular switch device, it is particularly challenging for the five high-power ports that require good linearity and isolation. The more I/Os there are, the more likely it is for wires to couple during use and bond. An UltraCMOS SP9T, such as the one in Figure 3, requires only four control lines, so this issue is less serious. Isolation is important because the coupling and bonding of signals can be detrimental to a multiband handset's performance. For instance, the PCS1900 transmit band overlaps with the DCS1800 receive band. Without isolation of 35 dB or better, unwanted in-band signals could pass through the filters and desensitize the receiver, which would result in dropped calls.</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgE1da4DQRH0FtcVuMkgcYZ4LrpzOB3gC8tqmKfRMLrz4QZTOgvbq3RF7j_jpVvOHisCppWRlkkrbdB64OEmZKCnUiK8K-Cc0g-cM6RckeGMJHmBy-HvX8lH3MsTX65EJHf9tUDxG4c1QQ/s1600/Dibujo1.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgE1da4DQRH0FtcVuMkgcYZ4LrpzOB3gC8tqmKfRMLrz4QZTOgvbq3RF7j_jpVvOHisCppWRlkkrbdB64OEmZKCnUiK8K-Cc0g-cM6RckeGMJHmBy-HvX8lH3MsTX65EJHf9tUDxG4c1QQ/s320/Dibujo1.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 3. The monolithic UltraCMOS PE42693 SP9T antenna switch offers 4-pin logic control with integral decoder/driver that facilitates 1.8 V and 2.75 V control</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"><span style="font-size: large;"><b>Small switches</b></span><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Despite the need for more switching capability, the real estate budget for the ASM is shrinking in new mobile handset designs. The need for highly integrated, small antenna switches becomes more pressing. New process technologies for multithrow switches and the use of CMOS is allowing unprecedented integration and shrinking footprints.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">For instance, a GaAs SP7T measures 2.4 mm2 whereas a comparable SP7T switch design using 0.5 µm silicon-on-sapphire (SOS) with equal or better small- and largesignal performance measures 1.2 mm2, a space savings of an extraordinary 50%. Currently available GaAs E/D pHemt or J-pHemt SP9T switches measure 2.85 mm2. An SP9T manufactured using an UltraCMOS 0.5 µm process measures 1.87 mm2 and does not require off-chip ESD devices or linearity enhancing matching components. A 0.25 µm UltraCMOS process is in the final stages of deployment, which will further reduce the size of the SP9T another 10%. Until recently, SP9T and SP7T switches were only available as wire-bond devices.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Recent process developments have led switch designers to flip-chip mount the switch to a low temperature co-fired ceramic (LTCC) substrate without underfill, eliminating the area previously required for wire bonding. This further reduces the device footprint. Currently, wafer-level chip-scale packaging (CSP) is in development to produce Ultra- CMOS switches that can be handled like a standard surface-mount package. Besides process technologies, another way to reduce the ASM's footprint is to increase integration, a common roadmap for all integrated devices. When manufactured in UltraCMOS, switches can eliminate the decoder, blocking capacitors, and the diplexer that are required with other non-CMOS switch technologies. Combined with CSP technology, this process can dramatically reduce the size and thickness of ASMs. In addition, inherent ESD tolerance and a monolithic CMOS interface simplify implementation and use. Finally, the high yield of UltraCMOS processes and scalability to additional switch throws provides a roadmap to higher levels of integration<br />
for future generations of handsets.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"><span style="font-size: large;"><b>Monolithic switches</b></span><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The technical requirements of the multimode, multiband GSM/WCDMA handset have exceeded the capabilities of traditional RFIC technologies such as GaAs (Table 1). Most critically affected by these ultrahigh performance specs are the antenna and the RF switch. As multiband architectures have grown, so has the requirement for the number of PAs and associated filters. But, in reality, the technical demand on the PAs has not changed, only the need for more PAs in a handset design. A critical challenge on the path to multiband handsets is finding an extremely efficient method to route all of the RF signals to the antenna—the monolithic switch. Fortunately, advanced CMOS processes are already in place to satisfy the increased demands on components in the RF signal chain of a multiband, multimode mobile handset. The integration capabilities of RF CMOS devices in the form of UltraCMOS RFICs solve many of these issues while maintaining peak performance.</div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;"><b>Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</b></div><div style="font-family: Georgia,"Times New Roman",serif;"><b>Bibliografia: http://rfdesign.com/mag/707RFDF4.pdf</b></div></div><span class="post-author vcard"> Publicado por <span class="fn">Jahir Alonzo Linares Mora</span> </span> <span class="post-timestamp"> en <a class="timestamp-link" href="http://s-organicos-ees.blogspot.com/2010/07/overcoming-rf-challenges-of-multiband.html" rel="bookmark" title="permanent link"><abbr class="published" title="2010-07-17T16:29:00-07:00">16:29</abbr></a> </span> <span class="reaction-buttons"> </span> <span class="star-ratings"> </span> <span class="post-comment-link"> </span> <span class="post-backlinks post-comment-link"> </span> <span class="post-icons"> <span class="item-control blog-admin pid-560967191"> <a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=8745186866698626526" title="Editar entrada"> <img alt="" class="icon-action" height="18" src="http://img2.blogblog.com/img/icon18_edit_allbkg.gif" width="18" /></a><a href="http://www.blogger.com/post-edit.g?blogID=7714433009753277815&postID=8745186866698626526" title="Editar entrada"> </a> </span> </span> <br />
<hr />Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-59576108057485513702010-06-27T22:08:00.002-04:302010-06-29T18:55:22.401-04:30Silicon RF capacitors set new standard for precision and stability<div class="post-body entry-content"><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Using a proprietary semiconductor process, <b>Vishay Intertechnology</b> introduced the industry's first silicon-based surface-mount RF capacitor family. The result was a new standard for high-precision capacitors (HPC) that raised the bar on stability over a broad range of frequencies as compared to conventional capacitors in low profile packages. In addition, the silicon-based surface-mount HPC RF capacitors offered high Q factors, low equivalent series resistor (ESR) values, low parasitic inductance, tight tolerances, and an ultrahigh self-resonant frequency (SFR). Now, the supplier has released a new member of this family in the miniature 0603 case size.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The high-performance, high-precision HPC0603A features SRF values as high as 13 GHz over a broad capacitance range from 3.3 pF to 560 pF. The E12 values available in this range provide extremely stable operation over a wide range of frequencies from 1 MHz to several Gigahertz. Parasitic inductance is a low 0.046 nH. Meanwhile, according to the manufacturer, HPC0603A devices that offer E24 values are scheduled for release in the near future.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">In addition, the new capacitor features high Q factors up to 4157, tight tolerances of ±1% or 0.05 pF, and low ESR values. The silicon process guarantees that every capacitor in the production line is within 1% tolerance, said Tony Troianello, marketing manager at Vishay's Integrated Products. Its construction makes it efficient, thus allowing it to handle up to 90 W without any change in the characteristics of the device, added Troianello. The HPC0603A measures 0.063 inches by 0.031 inches [1.60 mm by 0.80 mm] with a 0.022-inch [0.56 mm] height profile. It is rated for a temperature coefficient of capacitance (TCC) of ±30 ppm/°C over an operating range of -55°C to +125°C. Voltage options of 6 V, 10 V, 16 V and 25 V are available.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The HPC0603A's high capacitance range and relatively compact package enable increases in circuit Q, transmission range and reliability. HPC devices' unique construction (see the figure) reduces parasitics by shortening interconnecting traces on PCBs and improves circuit performance by decreasing the distance between components.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">This innovative design brings the new capacitor's SRF frequencies to new highs, enhancing performance and transmission/reception quality during operation at high frequencies. As a result, designers of wireless communications devices such as mobile and cordless phones, GPS systems, VCOs, filter and matching networks, RF modules, and base stations can implement HPC devices to reduce product size — simplifying design and reducing the number of components on the PC board — without sacrificing electrical performance.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">To predict end performance using simulation programs, a global model for these capacitors has been developed by Modelithics. Integrated with leading EDA tools, the model shows complete characteristics on a variety of PC boards and substrates. It also provides S parameters for these high-precision capacitors.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Samples of the HPC0603A are available, with lead times of up to 10 weeks for production quantities. Typical pricing for U.S. delivery in high-production quantities is $0.082 for 10-pF devices with a ±2% tolerance.<br />
<br />
<br />
Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF<br />
Bibliografia: http://rfdesign.com/microwave_millimeter_tech/passive_components/radio_silicon_rf_capacitors/</div><div style="clear: both;"></div></div><div class="post-footer"><div class="post-footer-line post-footer-line-1"><br />
</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-54061631769763853092010-06-27T21:53:00.002-04:302010-06-29T18:55:03.188-04:30Exploring advances in microwave and millimeter wave devices<div class="post-body entry-content"><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><span id="article_body">As the demand for higher bandwidth and frequencies in wireless and wirleline applications continues to climb, while cost and size continues to go downward, the need for better performing RF and microwave/millimeter wave ICs, discretes, modules and passive devices is far greater today. Thus, the efforts to improve components from capacitors at one end to millimeter wave monolithic ICs at the other extreme are in full swing. This report looks at some of these developments.<br />
<br />
For instance, in the RF and microwave power transistors arena, suppliers continue to tap advances in material science, process techniques, transistor structures, and packaging technologies to drive performance of lateral-diffused metal oxide semiconductor (LDMOS) FETs, gallium arsenide (GaAs) MESFETs, GaAs/InGaP and silicon germanium (SiGe) heterojunction bipolar transistors (HBTs), gallium nitride (GaN) heterostructure FETs (HFETs) and high electron mobility transistors (HEMTs), including silicon carbide (SiC) FETs, to new heights.<br />
<br />
While proponents like Agere Systems, Advanced Power Technology RF, Cree Microwave, Freescale Semiconductor (formerly Motorola Semiconductor), Philips Semiconductors, M/A Com, and STMicroelectronics amongst others continue to make significant improvements in RF LDMOS power transistors for wireless infrastructure applications, developers are tapping the benefits of new compound semiconductor material GaN with novel transistor structures to compete against LDMOS devices in the 2 GHz range. Due to their high breakdown field, high electron saturation velocity, high power density, and high operating temperature, AlGaN/GaN HFETs offer attractive alternatives to microwave power amplifier designers. For example, AlGaN/GaN HFET structures can achieve gate-to-drain breakdown voltages of around 100 V/µm and maximum current densities exceeding 1 A/mm, resulting in power densities several times higher than commercially available devices.<br />
<br />
</span></div><ul style="font-family: Georgia,'Times New Roman',serif;"><li><i><b><span id="article_body"> <br />
<div class="sheader">GaN-on-Silicon</div></span></b></i></li>
</ul><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><span id="article_body">To make it cost competitive with other technologies, work has been undertaken to develop GaN transistors on low-cost silicon substrates. Using its patented Sigantic GaN-on-silicon growth technology and 100 mm GaN wafer fabrication facility, Nitronex Corp. has developed RF/microwave power transistors for the output stage of 3G wireless base stations. The active device structure consists of a traditional GaN buffer, AlGaN barrier and a thin GaN cap layer (Figure 1). While the thickness and composition of the various layers is still undergoing optimization, the present design delivers RF peak efficiencies in the 65% to 70% range at 2.1GHz, stated Ric Borges, Nitronex's director of device engineering.<br />
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</span><br />
<span id="article_body"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiHr2dNfFUp41CYX_1H-Kf-lMb-DOJ_2zCBA4r0LjrNjefUJQTZDk8El07SZKxIb64HA_649lPdE2U1O50MKGKfSKfm-7BzI2T85yWMWaWADe1kUgIr-sovi_hgjunOCQH4yJ04IFPXi7c/s1600/fig8.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiHr2dNfFUp41CYX_1H-Kf-lMb-DOJ_2zCBA4r0LjrNjefUJQTZDk8El07SZKxIb64HA_649lPdE2U1O50MKGKfSKfm-7BzI2T85yWMWaWADe1kUgIr-sovi_hgjunOCQH4yJ04IFPXi7c/s320/fig8.JPG" /></a></div></span><span id="article_body"><br />
As a result, Nitronex is now sampling a 2.14 GHz, 20 W device, the NPT21120. Tested in application board with single carrier WCDMA 3GPP signal, this GaN HFET offers 18.2 W power at 27% efficiency with a gain of 13.6 dB, while achieving an adjacent-channel power ratio (ACPR) of -39 dB. Transistor dies were attached to a high thermally conductive CuW single-ended ceramic package using a AuSi eutectic process. The sources were grounded to the package base through backside vias in the 150 µm-thick silicon wafer. Operating at 28 V, the Idq is 2000 mA. Although, this part is undergoing qualification and full characterization, it is expected to go into production in the third quarter.<br />
<br />
Meanwhile, efforts are under way to scale down the gate length for higher-frequency response and implement new masks for improved voltage breakdown. The company hopes to extend the operating voltage to 40 V and beyond. While GaAs HFETs and HBTs share the same high-frequency capabilities as GaN HFETs, their operational voltage, despite recent advances, remains limited to 24 V to 28 V. This limitation is particularly acute in broadband designs, noted Borges.<br />
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GaN-on-silicon is also under development at M/A Com with plans to launch products sometime this year. While Nitronex and M/A Com prefer silicon substrate, Cree Research and Eudyna Devices, USA, a joint venture between Fujitsu Compound Semiconductor and Sumitomo Electric Co., have taken the SiC route. At last year's IEDM conference, Fujitsu Laboratories Ltd. of Atsugi, Japan reported a 100 W CW output power for a high gain AlGaN/GaN HEMT fabricated on an n-SiC substrate. Operating at 60 V, it achieves a linear gain of 15.5 dB and power-added efficiency (PAE) of 50% at 2.14 GHz. Unlike others, Freescale Semiconductor is investigating the performance of GaN on silicon, SiC, and sapphire substrates. It is looking at cost and performance trade-offs to provide optimal solutions.<br />
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Concurrently, HRL Laboratories LLC in Malibu, Calif. has developed a double heterojunction FET (DHFET) with improved performance over conventional single GaN HFET. According to HRL Lab's paper at IEDM, the DHFET exhibits three orders of magnitude lower subthreshold drain leakage current and almost three orders of magnitude higher buffer isolation than corresponding single HFETs. By comparison to single HFETs, the researcher shows 30% improvement in saturated power density and 10% improvement in PAE at 10 GHz for a GaN DHFET with 0.15 µm conventional T-gate.<br />
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</span></div><ul style="font-family: Georgia,'Times New Roman',serif;"><li><span id="article_body"> <br />
<div class="sheader"><i><b>Silicon solutions</b></i></div></span></li>
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<span id="article_body"><div class="sheader"> Meanwhile, for switching applications, advances in CMOS process are pushing silicon into the GaAs turf. Two key players offering CMOS switches include NEC's California Eastern Laboratories and Peregrine Semiconductor. Implementing its proprietary ultrathin-silicon-on-sapphire (UTSi) CMOS or UltraCMOS process, Peregrine Semiconductor has developed RF CMOS switches that have achieved higher speed with lower power consumption. They can deliver insertion loss, isolation, and switching performance that is competitive to switches based on gallium arsenide (GaAs) process technology for GSM handsets.</div><div class="sheader"></div></span><span id="article_body">According to Peregrine's director of marketing, Rodd Novak, UltraCMOS process uses a perfect insulating substrate to overcome RF leakage, isolation and power-handling limitations of standard CMOS to compete with costly pseudomorphic high-electron-mobility transistor (pHEMT) GaAs and other similar complex semiconductor processes. Peregrine's new switches are designed for GSM applications to switch the antenna to the receive or transmit path. For that, it has integrated on-chip functions like driver/decoder, LC filters and protection circuits, thus eliminating the blocking capacitors and the diplexer, normally required with GaAs switches.<br />
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Based on 0.5 micron UltraCMOSprocess, Peregrine has unveiled two types of RF CMOS switches. While PE4263 is a single-pole, six-throw (SP6T) CMOS switch for quad-band GSM handset antenna switch module (ASM); the PE4261 is a single-pole, four-throw (SP4T) version in a flip-chip packaging for dual-band GSM handset antenna switch.<br />
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On another front, Analog Devices launched an unprecedented monolithic RF variable-gain amplifier/attenuator (VGA) with precise high linearity output power control for wireless infrastructure applications. This single-chip RF VGA, ADL5330, is also the first monolithic VGA to provide broadband operation from 1 MHz to 3 GHz with a precision 60 dB linear-in-dB gain-control range, according to ADI. Unlike conventional discrete solutions that require many external components, the single-chip ADL5330 integrates broadband amplifiers and attenuators, offering considerable savings in board area, component count and solution cost as compared to discrete implementations. The precision linear-in-dB control interface further simplifies and eases circuit design. Based on its complementary bipolar (CB) XFCB-2 process, the ADL5330 provides 60 dB dynamic gain and attenuation (approximately +20 dB gain and -40 dB attenuation), an output power level of 22 dBm (1 dB compression point), an output third-order intercept (OIP3) of + 31 dBm at 1 GHz and a noise figure (NF) of 8 dB. The wide dynamic range of the ADL5330, combined with its low distortion and low noise, makes the device an ideal choice for transmit signal paths — at RF and IF frequencies — within wireless infrastructure equipment such as cellular base stations (CDMA, W-CDMA, GSM), point-to-point and point-to-multipoint radio links, satellite equipment, wireless local loop and broadband access services.<br />
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</span></div><ul style="font-family: Georgia,'Times New Roman',serif;"><li><b><i><span id="article_body"> <br />
<div class="sheader">Trends in passives</div><div class="sheader"></div></span></i></b></li>
</ul><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><span id="article_body">With the advent of WiMax, 3G, ultrawideband (UWB) and other data-intensive standards, the bandwidth, feature, size and cost pressures are constantly increasing. For instance, the ubiquitous cell phones are on a perpetual path of smaller form factor with ever more features. Consequently, designers are seeking miniaturized passive components with higher performance and lower cost, and investigating the possibility of integrating passive components on-chip.<br />
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The recently available EIA 0201 surface-mount technology (SMT) size measures 0.060 mm × 0.030 mm and is available in several materials including high-precision silicon or multilayer ceramic. Recently, Murata introduced capacitors in the 01005 size, which is half the size of the of the 0201 package (0.4 × 0.2 × 0.2 mm). Likewise, Vishay's Integrated Products Division is also planning on introducing capacitors in the 01005 small form factor capacitors. Leveraging the precision silicon capacitor's stability over a frequency range (Figure 3) Vishay plans on introducing silicon capacitors in the 01005 package. The capacitance will range from the 0.5 to 12 pF for high-volume manufacturing needs.<br />
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Although, direct conversion frequency transceivers minimize the need for filters, optimal RF performance still depends on inductors and capacitors with a high Q. Murata Electronics North America Inc. has a high-frequency inductor series in a 0201-size (0.6 × 0.3-mm) package. The surface-mount film inductors offer a low profile (0.3 mm) and a high Q value in high-frequency bands.<br />
<br />
Discrete components are also being developed to support the development and deployment of the UWB technologies in the 3.1 GHz to 5.0 GHz spectrum and other applications in the higher frequency spectrum. Because of the wide bandwidth, new components have been developed to provide balun or filtering devices in standard packaging sizes. Taiyo Yuden recently announced a bandpass filter in EIA 1206 case size. Likewise, exploiting the benefits of LTCC technology, Mini-Circuits has also readied a variety of passive components, including RF transformer, directional coupler and high-pass filter, in 1206 size packages.<br />
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While integration can save space, the cost and complexity of integrating digital, analog and RF functions onto a single chip has proved costly and difficult to commercialize. Although, the trend is to integrate all functions onto a single chip, the challenges associated with system-on-a-chip (SoC) is meeting the application needs while still being able to manufacture in a cost-effective manner.<br />
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Within the high-density packaging arena or HDP there are demands for smaller and higher precision manufactured passive components. Typically, SIPs are vertically bonded chips using chip scale packaging (CSP) techniques. Passive components are included into SIPs via either an integrated passive device (IPD) or machined components.<br />
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One of the benefits of IPD is the reduction of parasitic inductance or capacitance, which is needed with higher-speed circuits. Also, chips are operating at increasingly lower voltage levels. However, the noise that is generated by the fast switching speeds is not decreasing in a proportional fashion, even with the reduction in size offered by IPD technology. Hence, there is an additional need to decrease the parasitic inductance through technology. To address this need for reduced inductance, technology developed by X2Y on IPDs includes layers of ground between the electrode and cathode. Because the current directions change as the result of the layered grounds, the overall effective inductance is less than with standard multilayer ceramic chip capacitors (MLCC).<br />
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IPDs are also tapping the relatively new technology, namely RF micro-electro-mechanical systems (MEMS). Passive components based on RF-MEMS are becoming increasingly integrated into RF modules. As the bottoms up development of the MEMs building block components matured the production of various passive solutions such as film bulk acoustic resonator (FBAR) by Agilent Technologies is being observed. RF-MEMs are especially well suited for the applications such as switches, capacitors, inductors, resonators and microwave guides. RF MEMs offer performance advantages such as high tuning ratio of MEMs tunable capacitors and high-quality factor of MEMs-based inductors. However, packaging of the MEMS onto microelectronics remains challenging.<br />
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Although the RF-MEMS Q factors do not match their discrete counterparts, tunable capacitors have been developed with relatively high Q and tunability. In a recent paper, tunable inductors with Q of 150-500 over a frequency range of 1 GHz to 6 GHz have been developed. The tunability was shown to be 17. Even though static spiral inductors have been integrated into products, tunable inductors are not as well developed as capacitors due to high losses. However, static inductors have reached commercial viability with the available spiral inductors that have quality factors of 55 GHz at 2 GHz and inductance values ranging from 1.5 nH to 15 nH.<br />
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</span></div><ul style="font-family: Georgia,'Times New Roman',serif;"><li><b><i><span id="article_body"> <br />
<div class="sheader">Emerging applications</div></span></i></b></li>
</ul><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><span id="article_body">At the upper reaches of the microwave frequency spectrum where millimeter (mm) wavelengths reside — between 30 GHz and 300 GHz — current and emerging applications are in the early stages of creating a demand for monolithic microwave integrated circuits (MMICs) based on gallium arsenide (GaAs) technology. Some portions of the commercial mm-wave band that employ MMICs have been active for a number of years: digital radio transceivers for cellular communications backhaul and ground terminal transceivers for very small aperture terminals (VSATs) are the two major applications. Digital transceivers cover the radio bands from 6 GHz through 42 GHz while most VSATs now operate in the Ku band (12 GHz to 18 GHz) but in the future will be moving higher in frequency to Ka band (26 GHz to 40 GHz). Most of the excitement, however, for the future growth of mm-wave technology lies in recent developments at E-band (60 GHz to 90 GHz).<br />
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In October 2003, the Federal Communications Commission (FCC) opened the 70 GHz, 80 GHz and 90 GHz bands for the deployment of broadband mm-wave technologies. Specifically, the commission adopted rules for commercial use of the spectrum in the 71 GHz to 76 GHz, 81 GHz to 86 GHz and 92 GHz to 95 GHz bands. These bands are intended to encourage a range of new products and services including point-to-point wireless local-area networks and broadband Internet access. Point-to-point wireless is a key market for growth since it can replace fiber-optic cable in areas where fiber is too difficult or costly to install. But the real high volume action at mm-wave will likely be in the automotive radar market at 77 GHz. While only available in high-end automobiles at present, cost reductions in MMIC chip manufacturing could lead to significant deployment in all cars in the not too distant future. Such radars will not only be used for collision avoidance and warning, but also for side- and rear-looking sensors for lane changing, backup warning and parking assistance. When this market and others reach full potential in a few years, demand for mm-wave MMICs could increase dramatically from today's rather modest levels.<br />
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Because of today's limited applications at frequencies above 30 GHz, the MMIC offerings of many manufacturers are in the early stages of development. When looking through manufacturer's data sheets it is not uncommon to see any number of devices marked as "prototypes" and hence not ready for design use in systems. Nevertheless, products are beginning to arrive on the market. Agilent Technologies, for example, just released a number of second-generation devices in its AMMC series of pHEMT MMICs. The family is intended for point-to-point radio links in microwave base stations. Among the new products being offered is the AMMC 6241, a low-noise amplifier (LNA) rated from 26 GHz to 43 GHz with a gain of 20 dB and a noise figure (NF) of 2.7 dB Power and driver amplifiers are key elements of all communications systems and two of the new devices in the series are noteworthy: the AMMC 6440 is a 1 W (P1dB of 28 dBm at 42 GHz) power amp and the AMMC 6345 is a driver amp with a P1dB rating of 24 dBm and a gain of 20 dB at 40 GHz.<br />
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TriQuint Semiconductor is a company with a variety of recently introduced amplifiers in the mm-wave range. Just last month, three ultrawideband MMICs were released spanning the range from dc to 40 GHz. The TGA4830-EPU offers a P1dB of 11.5 dBm, a gain of 13 and a typical noise figure of 3.2 dB. A medium-power MMIC, the TGA4832-EPU is specified for a P1dB of 18dBm and a 3 dB automatic gain control (AGC) range. Applications include use as a driver for 40 Gb/s optical modulators. The TGA4036-EPU is another medium-power amplifier whose saturated output power is 22 dBm, small-signal gain of 20 dB and 8 dB input/output return loss. Point-to-point and point-to-multipoint communications are typical applications.<br />
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Millimeter-wave LNAs with very low noise figures are featured in the product line of Eudyna Devices, USA, a joint venture between Fujitsu Compound Semiconductor and Sumitomo Electric Co. The FMM5703VZ is a packaged device spanning 24 GHz to 32 GHz with a typical noise figure of 2.5 dB and a gain of 17 dB. The FMM5709 is available in two versions: the packaged VZ and in chip form (X). Both cover the 24 GHz to 30 GHz range with the VZ having a noise figure of 3.5 dB and a gain of 21 dB and the X version's noise figure of 2.5 dB and a gain of 23 dB. The VZ is a ball-grid array, surface-mount package<br />
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System designers who need a complete MMIC function on a single chip can go to manufacturers such as Mimix Broadband, which recently announced the 29REC029 subharmonic receiver. The highly integrated device incorporates a three-stage balanced LNA followed by an image-reject anti-parallel diode and a local oscillator buffer amplifier. It operates over the 24 GHz to 34 GHz band and is aimed at wireless communication applications such as local multipoint distribution systems (LMDS) and satellite communications. The company also offers LNAs, buffer amps and power amps up to 43 GHz.<br />
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With MMICs for automobile radar systems appearing on the horizon, GaAs manufacturers such as United Monolithic Semiconductor are making inroads into the market with devices for short-range radar (24 GHz) and long-range radar (77 GHz). The company, a joint venture between French and German interests, offers a range of automobile radar products such as LNAs, frequency multipliers and mixers that operate in the 76 GHz to 77 GHz band. The CHA1077, for example, is a 77 GHz LNA with a noise figure of 4.5 dB and P1dB power rating of 10 dBm. Two frequency-multiplier devices, the CHU2277/3277, take 38 GHz to 38.5 GHz input frequencies and convert them into 76 GHz to 77 GHz outputs.<br />
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Once you get into the upper end of today's working mm-wave spectrum at E-band, product offerings begin to quickly drop off. But Velocium Products recently interjected itself into this market with a number of devices aimed at the 71 GHz to 76 GHz and 81 GHz to 86 GHz communications frequencies and 76 GHz to 77 GHz automotive radar range. Using semiconductor processes obtained from Northrup Grumman Space Technology, the company announced the APH series of HEMT power amplifiers. Now in engineering sampling, the APH 576 is an 81 GHz to 86 GHz power amplifier whose P1dB output power is 20 dBm. The APH 577/578 operates from 83 GHz to 86 GHz with a P1dB power of 18 dBm.<br />
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While today's market for mm-wave MMICs trails well behind that of cellular phones, wireless LANs and other applications at the lower end of the GHz frequency spectrum (1 GHz to 5 GHz), the potential for growth in the not too distant future is bright. The key areas for opening up mm-wave technology appear to be in the automotive radar and point-to-point wireless as a last-mile interconnect replacement for fiber-optic cable.<br />
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Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF<br />
Bibliografia: http://rfdesign.com/microwave_millimeter_tech/passive_components/radio_exploring_advances_microwave/</span></div><div style="clear: both;"></div></div><div class="post-footer"><div class="post-footer-line post-footer-line-1"><br />
</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-63716832913709108102010-06-27T21:41:00.002-04:302010-06-29T18:54:39.946-04:30ESD-protected RF filter with on-chip passive and active elements<div class="post-body entry-content"><div style="text-align: justify;"><span class="deck"><span style="font-family: Georgia, 'Times New Roman', serif;">A monolithic integrated multiband PCN/PCS RF-bandpass filter manufactured on highly resistive silicon substrate with mode conversion and ESD protection is described. In order to analyze the ESD behavior of the filter, an ESD simulation model is presented and compared with measurement results.</span></span></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Integrated passive devices such as resistors, capacitors, coils and transformers have been introduced by several companies<num></num>. Extended failure analysis revealed that electrostatic discharge (ESD) and electrical overstress (EOS) are the reason for approximately half of all circuit failures for integrated devices. Thus, excellent ESD protection is becoming more important. High ESD robustness of the circuits guarantees high yield in production, and additionally reduces the field failure rate of applications<num></num>. The most popular ESD models are the human body model (HBM), the machine model (MM), and the charged device model (CDM). The last one is of growing interest because it is a special kind of electronic discharge, showing good agreement with present ESD failure mechanisms in chip manufacturing. Each model describes a special kind of ESD discharge and is further classified into different ESD classes.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">In order to protect integrated filter circuits from ESD, ESD devices are either placed as discrete circuits around the critical input/output pins or integrated with the filter onto the chip. The last concept leads to a cheaper and smaller PCB outline<num></num>.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">For the development of RF filters, a compromise between RF performance and ESD protection must be found. The non-linearities of active ESD devices, for example, can cause intermodulation and degrade the RF performance.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The new RF bandpass filter with integrated impedance matching, mode conversion and ESD protection is manufactured with an extended silicon-copper technology that allows integration of active and passive components on a single die. In the following sections, an RF filter with excellent ESD protection and filter performance will be discussed, and an analytical HBM simulation setup for these filters will be introduced.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="sheader" style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><ul><li><i><b>Si-Cu technology</b></i></li>
</ul></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">An existing silicon-copper technology for passive integration was extended in order to integrate passive and active elements on a high-resistive Si substrate. Figure 1 shows the cross-section of the layer sequence for a typical RF filter with monolithic integrated planar inductors, metal-insulator-metal (MIM) capacitors, and ESD diodes.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4rmHEQ4qc8mCRqpsNOZCyY_A-NKtNW2w0oJZSm-a1T1QFXTBYeXC_IeCINZp19x8g5_b-rXapHH3c-GFuS-ceVQ7muSynRmuT050aZURwL-U470ZhABewxqP8rb_kH49YoU_EAixGR0Q/s1600/cosas5.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi4rmHEQ4qc8mCRqpsNOZCyY_A-NKtNW2w0oJZSm-a1T1QFXTBYeXC_IeCINZp19x8g5_b-rXapHH3c-GFuS-ceVQ7muSynRmuT050aZURwL-U470ZhABewxqP8rb_kH49YoU_EAixGR0Q/s320/cosas5.JPG" /></a></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: center;">Figure 1. Cross-section of the chip with a three-layer copper metallization<br />
embedded in SiO2.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Coils and transformers are implemented in three-layer copper metallization. Metal-1 has a thickness of 600 nm and is mainly applied to lead through the metallization from the inside to the outside of the coils. Metal-2 and metal-3 have thicknesses of 2500 nm and are used for adjusting the coils to the required inductance. Due to the performance limitation of the skin effect, these stacked coils can be used for RF applications above 1 GHz. For lower-frequency applications, an increase of the copper layer thickness would be necessary to improve the quality factor (Q) of the inductors substantially. The inductances of typical integrated coils are in the range of 0.5 nH to 35 nH, with corresponding Q factors between 10 GHz and 16 at 1 GHz. Maximum Q values of about 40 were measured at 3 GHz for a corresponding L value of 0.5 nH.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The Al<num><sub>2</sub></num>O<num><sub>3</sub></num> MIM capacitors, which are necessary for the implementation of on-chip resonators, are placed between metal-1 and metal-2. With the new dielectric material, high specific capacitance values of from 1.4 fF/µm<num><sup>2</sup></num> to 1.8 fF/µm<num><sup>2</sup></num> can be achieved leading to small capacitor dimensions and small outlines of the chip design. The values for the MIM capacitors are in the range of between 0.1 pF and 30 pF, with corresponding Q factors of 100 at 1 GHz.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="sheader" style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><ul><li><i><b>Bandpass filter with mode conversion</b></i></li>
</ul></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">With the extended S technology, filters with low insertion loss and high harmonic suppression can be designed. An integration of filter elements and balun on-chip replaces a high number of external SMD components, leading to reduced board space and lower assembly costs. Further advantages compared to discrete solutions are smaller component tolerances of these integrated devices and a reduced assembly error rate.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIND3mtVKn8Q09O14tJ95WwUzueDd7uIisRPFEgsgeEHXNgO4VsAEtv6AfiZo-l8m1fy4Yp84cdzVdpVfRV_dKXcRkQ52WeSjVz_vZYJY2i4wLbfEJYjhvxKWJDxm4KG5_bU8yoBkdGUk/s1600/cosas6.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIND3mtVKn8Q09O14tJ95WwUzueDd7uIisRPFEgsgeEHXNgO4VsAEtv6AfiZo-l8m1fy4Yp84cdzVdpVfRV_dKXcRkQ52WeSjVz_vZYJY2i4wLbfEJYjhvxKWJDxm4KG5_bU8yoBkdGUk/s320/cosas6.JPG" /></a></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: center;"> Figure 2. Bandpass fi lter with mode conversion for PCN applications<br />
consisting of passive elements (coils, transformers and MIM capacitors),<br />
as well as active elements (ESD diodes).</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The schematic of the implemented PCN/PCS bandpass filter (1710 MHz to 1910 MHz) with mode conversion from differential to single ended is shown in Figure 2. The filter consists of a symmetrical filter design based on several optimized LC resonators. The mode conversion is carried out with an integrated autotransformer with a coupling factor of 0.83.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">We focused on a high common-mode suppression at the second harmonic, leading to a symmetrical filter design. This design reduces the influence of the grounding to the common-mode signal, which results in an excellent common-mode suppression of about -40 dB at the second harmonic. In addition, the symmetrical design allows implementation of a dc biasing network in the mirror plane of the filter, acting as a dc current supply typically used to drive the modulators of a transceiver. The bandpass filter itself is housed in a thin, small, and leadless package with dimensions of only 2.0 × 1.3 × 0.4 mm.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Coils and autotransformers were considered in the simulation tool by de-embedded S-parameter measurements and a Spice netlist generated by a simulation tool, respectively. The parameters of the autotransformer model are extracted from its geometrical structure by applying a numerical solver for the electric and magnetic fields.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Figure 3 and Figure 4 show the insertion loss versus frequency and the common-mode suppression of a harmonic PCN/PCS filter, respectively. The insertion loss within the passband (1710 MHz and 1910 MHz) is about -2.5 dB, with a corresponding ripple of only 0.2 dB.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtCGw8wclH_x4iPkeQgF9OOEgRofCmcXR6dLbHagKlN2Ua5YBKYMCpvlSEMKqne8TDoyt4fXBtqr_VddoAUPNFBa_hZIjmRfMtVEDLCSDkws271h3hdvjpkiVJTeGUR9_dTi5yczdhGWs/s1600/cosas7.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtCGw8wclH_x4iPkeQgF9OOEgRofCmcXR6dLbHagKlN2Ua5YBKYMCpvlSEMKqne8TDoyt4fXBtqr_VddoAUPNFBa_hZIjmRfMtVEDLCSDkws271h3hdvjpkiVJTeGUR9_dTi5yczdhGWs/s320/cosas7.JPG" /></a></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: center;">Figure 3. Comparison of simulation and measurement results for the<br />
differential mode of the bandpass fi lter.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2Ptj9vZndC66bSrWQrewQSVDdeuzPALXNDerT9IOD_BDsYjeZ0akhBBiyNjNafXAB378rPqI_ap76ierD1bt-3phkwS_7p2u_saZQQfLuTQjLPeOorZON5Us9X-ZjBSIVrWBxjxSnvOQ/s1600/fig1.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2Ptj9vZndC66bSrWQrewQSVDdeuzPALXNDerT9IOD_BDsYjeZ0akhBBiyNjNafXAB378rPqI_ap76ierD1bt-3phkwS_7p2u_saZQQfLuTQjLPeOorZON5Us9X-ZjBSIVrWBxjxSnvOQ/s320/fig1.JPG" /></a></div><div style="text-align: center;">Figure 4. Comparison of simulation and measurement results for the<br />
common-mode suppression of the bandpass fi lter.</div></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The suppression of the third harmonic is below -40 dB and in good agreement with the simulation results.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Using an autotransformer instead of a simple LC balun leads to an improved common-mode suppression of -30 dB in the frequency range between 3 GHz and 6 GHz. However, the simulation and measurement results differ at higher frequencies because of the implemented autotransformer model, which is only valid up to half of the self-resonance of the autotransformer itself.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div class="sheader" style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><ul><li><i><b>ESD model</b></i></li>
</ul></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">EOS and ESD damage affects device functionality and RF performance. Therefore, it is important to make thorough investigations concerning ESD protection, especially for the MIM capacitors, in order to guarantee the required ESD robustness.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Figure 5 shows a complete ESD simulation setup consisting of the implemented ESD model (HBM, MM or CDM), the parasitics of the measurement setup, and the device under test (DUT). The investigations are focused on HBM, with corresponding values for R<num><sub>M</sub></num> = 1500 Ω, C<num><sub>M</sub></num> = 100 pF, and L<num><sub>M</sub></num> = 0 nH <num><sup>5</sup></num>.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgOqxA_0pppfF9Ojzu_DbhvzV0SN4R7V4q7ucoGn5o5749Wz3shmKqxJiITfgcg47WDPBANp7zufal6SGi0ToT6X7UDlnNSRBstbtYyzGGpFB5gfbtKSINc6QL9LJkfrankFXQTgAnkHLA/s1600/fig2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgOqxA_0pppfF9Ojzu_DbhvzV0SN4R7V4q7ucoGn5o5749Wz3shmKqxJiITfgcg47WDPBANp7zufal6SGi0ToT6X7UDlnNSRBstbtYyzGGpFB5gfbtKSINc6QL9LJkfrankFXQTgAnkHLA/s320/fig2.JPG" /></a></div></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">In order to investigate the ESD protection of the filter sub-circuits (L<num><sub>D</sub></num> || C<num><sub>D</sub></num>), a simple ESD model was developed. First of all, parasitic board elements are neglected so that only the parameter for HBM and the filter sub-circuit are considered. For this case, a linear differential equation of third order with the general solution is obtained.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><table border="0" cellpadding="5" cellspacing="0" style="font-family: Georgia,'Times New Roman',serif; margin-left: 0px; margin-right: 0px; text-align: left; width: 245px;"><tbody>
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</tbody></table><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="http://rfdesign.com/microwave_millimeter_tech/passive_components/esdrf-09-eq01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="46" src="http://rfdesign.com/microwave_millimeter_tech/passive_components/esdrf-09-eq01.jpg" width="245" /></a></div><b>x</b>(t) = (U<num><sub>CM</sub></num>, U<num><sub>CD</sub></num>, I<num><sub>LD</sub></num>)<num><sup>T</sup></num> is the state vector corresponding to the state variables of the electrical network, where A represents the system matrix.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><table border="0" cellpadding="5" cellspacing="0" style="font-family: Georgia,'Times New Roman',serif; margin-left: 0px; margin-right: 0px; text-align: left; width: 289px;"><tbody>
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</tbody></table><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">With the initial conditions for current and voltages, the vector x<num><sub>0</sub></num> is given by (U<num><sub>0</sub></num>, 0, 0)<num><sup>T</sup></num>.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="http://rfdesign.com/microwave_millimeter_tech/passive_components/esdrf-10-eq02.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="175" src="http://rfdesign.com/microwave_millimeter_tech/passive_components/esdrf-10-eq02.jpg" width="289" /></a></div>Figure 6 shows the simulation results of equation 1 for the voltage drop at the capacitor C<num><sub>D</sub></num> (1 pF) for different L values ranging from 1 nH to 30 nH. Improved ESD protection for the capacitor C<num><sub>D</sub></num> can be achieved with smaller values of the inductance L<num><sub>D</sub></num>. Additionally, the inductor L<num><sub>D</sub></num> of the LC resonator determines the pole of the transfer function and is, therefore, important for the overall filter performance.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilnkvBa5DYfCDNxvoodgm9ARlhyphenhyphenXY4gn4_jEg88SiCfMcOByVeIlt6WrLeaLmE5PcUNYYr16GHYCm_01JToqjY3iBtaDszF1XEf_T8ngrsEPB40WnaAbMX0i7geQpOv_1fIjFLmhJC7TQ/s1600/fig4.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilnkvBa5DYfCDNxvoodgm9ARlhyphenhyphenXY4gn4_jEg88SiCfMcOByVeIlt6WrLeaLmE5PcUNYYr16GHYCm_01JToqjY3iBtaDszF1XEf_T8ngrsEPB40WnaAbMX0i7geQpOv_1fIjFLmhJC7TQ/s320/fig4.JPG" /></a></div><div style="text-align: center;">Figure 6. Simulated voltage at the capacitor CD (1 pF) for an LC sub-circuit.<br />
HBM model (U0 = 1 kV).</div></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">To investigate the complete ESD setup, the board parasitics must be determined and included in the circuit simulator. The parameter extraction for the board parasitics is carried out in the following manner: First, the measurement equipment is characterized by current discharge for different terminations (0 Ω and 500 Ω) for the DUT, with which the board elements can be determined. Figure 7 shows simulated and measured results for a shorted device under test.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZvx2P8ZigAEjiCFscb-HC7an0uoek2iNkSIjvFhKcaYVKWSXJMKvrqEubZckv8eCv6Mdb99f-8FDMPIDsOR4Rb3Srtk1gUl5nK9QaRvJP6Qg-CICn0w6KBcuGFRxcAeg3-4j8DjsEfUc/s1600/fig5.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZvx2P8ZigAEjiCFscb-HC7an0uoek2iNkSIjvFhKcaYVKWSXJMKvrqEubZckv8eCv6Mdb99f-8FDMPIDsOR4Rb3Srtk1gUl5nK9QaRvJP6Qg-CICn0w6KBcuGFRxcAeg3-4j8DjsEfUc/s320/fig5.JPG" /></a></div><div style="text-align: center;">Figure 7. Measured and simulated results of the current discharge for a shorter device (Rd=0)</div></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">Transient simulations for the PCN/PCS bandpass filter with internal active and passive elements were carried out with the circuit simulator (ADS) from Agilent. Figure 8 shows the simulation results of the voltage drop for several MIM capacitors and reveals the endangered element for ESD damage.</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div class="sheader" style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"><ul><li><i><b>Conclusion</b></i></li>
</ul></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;"></div><div style="font-family: Georgia,'Times New Roman',serif; text-align: justify;">The performance of a monolithic integrated PCN/PCS RF bandpass filter with mode conversion, integrated dc power supply and ESD protection was discussed. Good RF filter performance in combination with ESD protection was achieved. The figure of merits of the RF filter are the insertion loss within the passband of -2.5 dB, the third harmonic suppression of -45 dB, the common mode suppression of -40 dB, and the ESD robustness of more than 3 kV.<br />
<br />
Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF<br />
Bibliografia: http://rfdesign.com/mag/611RFDF1.pdf<br />
<br />
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</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-13403247301251020262010-06-27T20:50:00.002-04:302010-06-29T18:54:17.973-04:30Alternative to SMT for microwave and millimeter-wave systems<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">When faced with the challenge of reducing the size and improving the manufacturing efficiency of complex microwave and millimeter-wave systems, engineers will often turn to surface-mount technology (SMT). Conventional SMT works well for frequencies up to about 6 GHz. However, at higher frequencies SMT is usually not a viable option because in SMT topology the transmission lines are unshielded, and the components do not have adequate grounding. This results in unwanted radiation, coupling and regeneration.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Another problem with RF SMT systems is the lack of an easy way to characterize the performance of the individual microwave components. With traditional connectorized components you can easily connect them to the ports of your test equipment and get an accurate characterization. With SMT components, you would need to either find, or more likely, design and fabricate a suitable test fixture that will allow the device to be connected to the ports of the test equipment. And, the test results are often inaccurate due to the differences in the launch conditions and related parasitic losses of the device when measured in the test fixture as compared to when the device is mounted to the SMT board.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><span style="font-family: Georgia, 'Times New Roman', serif;">Figure 1. The interconnect and the outer conductor</span><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">of the Ultra Package.</span><br />
<div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgexjaUkQfjzyUngW7X2ZYWHJ0SZpjMfoZe2ZLwBFDRmZ8EBWcE8rBYDJjuiOYUstdAlRppz6bidUyqmT-972qNFgsCKiRPEQZ69gTEkknZByV-C-bGYmB_-kwMNeCYYTFza2lP2uzeqLs/s1600/cosas1.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgexjaUkQfjzyUngW7X2ZYWHJ0SZpjMfoZe2ZLwBFDRmZ8EBWcE8rBYDJjuiOYUstdAlRppz6bidUyqmT-972qNFgsCKiRPEQZ69gTEkknZByV-C-bGYmB_-kwMNeCYYTFza2lP2uzeqLs/s200/cosas1.JPG" width="200" /></a>For these reasons, reducing the size and increasing the level of integration of microwave and millimeter-wave systems requires an alternate approach. By using unique device packaging, and an innovative approach for cascading the devices, these high-freq-uency systems can be assembled with predictable results. And, an added benefit is a significant reduction in frequency response ripple without the need for isolators between the individual components. This is due to the reduction of the electrical length between the microwave components.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Desirable characteristics of the individual component packages require a package that is small in size, and can operate at frequencies up to 70 GHz and that can be connectorized for easy device characterization. Also, it should be able to be placed in a component chain in a way that reduces the possibility for RF leakage that could lead to regeneration. These desirable characteristics, along with the need for good thermal dissipation, component mounting, RF grounding, and easy connectorization for device characterization should be considered when designing a package.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">One such package is the Ultra Package developed by B&Z Technologies. This package is small, measuring only about 0.4" × 0.4" × 0.1." It operates well up to 70 GHz. This is due to its small coaxial RF feed-through size with pin diameters of 0.009," the design of the microwave cavity and the package mounting features. The small feed-throughs minimize the possibility for higher-order mode excitation. The package is easy to connectorize to allow precise device characterization. Also, the microwave cavity is designed to reduce any waveguide effect. And finally, the cavity is configured in a way to allow efficient launching to 0.1 mm thick discrete devices. Most high-frequency discrete devices and MMICs are 0.1 mm thick. These packages work well with available MMICs. These would include VCOs, amplifiers, attenuators, mixers as well as circuits consisting of individual discrete devices.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The technique to cascade this type of package is simple but effective. The obvious first step is to package the microwave component and characterize its performance. Then, starting at one end of the RF chain, the first device is mounted in place. Then, a female-female interconnect (Figure 1) is placed on the RF pin that is to be connected to the next device in the RF chain. Next, the outer conductor block is placed over the RF pin with the interconnect already in place. Finally, the next device is slid into place, making sure its input pin engages the other end of the interconnect that is on the first component (Figure 2). To prevent unwanted radiation, these two cascaded components need to be held under end-end pressure to ensure the outer conductor makes full contact with the component housings. This pressure is maintained with cam-screws. These cam-screws can be easily made from existing commercial hardware by machining the head of a machine screw so that the head is eccentric to the major diameter of the screw threads.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu7sUGUmKXI2yfkOKYgZRUMlMJOBbQQCogFKnN-v-K8_msuPuzHvSucXx4abNHDYeMmbbZ8a9axFnfRFH070uX6O2EbhNMfOG8F_QRHzpmqLVU_sS9EgLXCGw4VD3BvN585vb4t4gkgDs/s1600/cosas2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu7sUGUmKXI2yfkOKYgZRUMlMJOBbQQCogFKnN-v-K8_msuPuzHvSucXx4abNHDYeMmbbZ8a9axFnfRFH070uX6O2EbhNMfOG8F_QRHzpmqLVU_sS9EgLXCGw4VD3BvN585vb4t4gkgDs/s320/cosas2.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;"> Figure 2. With the Ultra Package, a completely assembled millimeter-wave<br />
downconverter is only 2.5 inches long. It exhibits excellent isolation and<br />
small size at millimeter-wave frequencies.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Further units can be cascaded by following the previous steps. The ends of the RF chain can be terminated with various types of interfaces. For example, the ends can be terminated directly with a waveguide without the need for adding a pair of connectors. The RF connections can also be standard 3.5 mm, 2.92 mm or 1.85 mm coaxial connectors. Where necessary, the input and/or output configuration can be coplanar, strip line or microstrip transmission lines.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Bibliografia: http://rfdesign.com/microwave_millimeter_tech/passive_components/radio_alternative_smt_microwave/</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-84643289216921112322010-06-27T20:40:00.003-04:302010-06-29T18:53:56.344-04:30Use coplanar waveguide probes for accuracy and repeatability of RF measurements<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">As consumer devices like cell phones, laptop computers and PDAs get smaller, users are now expecting more functions in a single piece of equipment. They want that one little powerhouse to be easy to use, extremely reliable and smaller than a bar of soap. Consequently, highly specialized components and assemblies used in these and other demanding applications are operating at higher frequencies and must meet tighter performance specifications.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Thus, 0201s are now favored because they are 75% smaller and occupy 66% less board space than the 0402s they typically replace. With packages, typical SMD lead pitches and micro BGA bump pitches are as small as 0.5 mm. Much smaller interconnects on boards and assemblies, with conductor traces less than 4 mils (0.1016 mm), also challenge the test milieu.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">As for frequency, commodity commercial products are at 6 GHz, CPUs on board interfaces have 10 GHz bandwidth, and telecommuni-cations devices operate at 10 Gb, 20 Gb and 40 Gb. Increased performance is also expected in SOICs, for example, where more functions are demanded from the same area. This means more electrical contacts to effectively stimulate, and a higher mix of signal types, and some of these are always at a higher bandwidth.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">With these changes in electronic components and assemblies, quality engineers feel the dual pressures of working with objects that are too small to see and touch yet are simultaneously held to higher standards for precision and reliability. To meet these challenges, precise, affordable probe stations have been created to handle the more difficult test regimens required by the changes mentioned above.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">These probe stations also have microwave test accessories available, as well as test cables specifically designed for microwave microprobe testing, and precise thin film network (TFN) adapters for coplanar waveguide to microstrip circuits and MMIC sub-assemblies. Some manufacturers offer a wide range of sizes, features and prices that fit the needs of any size lab. Before offering a brief summary of microprobe testing equipment, however, there are issues to consider regarding fixturing and setup of several specific types of components.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><span style="font-size: small;"><i><b>Issues to consider</b></i></span></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The use of coplanar and coaxial microprobes has made many microwave measurements easier and more accurate. However, there are many products, including FETs, MMICs, chip capacitors, chip resistors, and chip inductors that are designed for microstrip applications. None of these products have the required signal and ground pad orientation and the required spacing to allow microprobing. These devices will generally be wire bonded into a circuit, so that the wire bond becomes one of the circuit elements.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Consequently, it is desired that the measured S-parameters of this device also include the bond wire response. For example, a low-noise GaAs FET die will generally be die attached to a metalized ceramic substrate, and the gate, drain, and source are bond wired, using short double bonds, to the specified pads on the substrate. Note that the bond wire lengths of the test samples must be identical with the specific application.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Until recently, these measurements have been difficult and tedious. Now, a new set of adapters and associated calibration technique makes these measurements straightforward. The adapters, shown in Figure 1, adapt a coplanar probe to a microstrip, which connects to the device under test (DUT) with bond wires.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Double bonds, as used in the actual application, connect the gate and drain metallization to the adapter microstrip. The source metallization is wire bonded to the ground plane, which is common to the entire setup. Any gold metalized conductor works well for the carrier. The DUT dice and the adapter substrates are either attached with silver epoxy or eutectic solder, as required.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Having looked at this particular concern that affects microprobe testing of some component types, three brief case histories will be presented, followed by a summary of the range of equipment available for microprobe testing.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgslAFclFlHhyphenhyphenwlagG9UedELALqqBiUJgRaPOIacsvRNLOCiIq2yaO5YJKy9S1E04zF-zG05M1l4SFipoen65cgTRBJuGk5wEJx54L6dxGxxpeIrsNc9Rd5OxwXgFN_uUMy0e9Zm15oVI/s1600/teles.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgslAFclFlHhyphenhyphenwlagG9UedELALqqBiUJgRaPOIacsvRNLOCiIq2yaO5YJKy9S1E04zF-zG05M1l4SFipoen65cgTRBJuGk5wEJx54L6dxGxxpeIrsNc9Rd5OxwXgFN_uUMy0e9Zm15oVI/s320/teles.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">Figure 1</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>Three brief case histories</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">These case histories<num></num> demonstrate the essence of adapter substrate technology, and illustrate the effectiveness of coplanar to microstrip transitions compared to coaxial to microstrip transitions.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">After a broadband bandpass filter in the Q band was designed, the circuit was tested using a test fixture. Several poles in the in-band response of the filter and the high insertion loss, caused by the double coaxial-to-microstrip transition, were observed. In order to eliminate all inaccuracies of the test method that masked the actual behavior of the circuit, and to obtain an accurate measurement up to 50 GHz, a coplanar to microstrip transition connected to a coplanar probe station was used. Using the coplanar to microstrip transition to test the filter, the tested results were quite close to the simulations.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Several microstrip broadband attenuators were designed with a topology that provides constant attenuation over broad bandwidth with good input and output matching, which requires a reliable test fixture. The use of coplanar transitions provided accurate measurements. One attenuator of 3 dB is shown in Figure 3a and the attenuation and matching tested.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">In a circuit design, it is important to have an accurate model or characterization of the active device. Before designing some amplifiers in the Q band, an EC2612 GaAs pHEMT transistor was tested using the coplanar to microstrip transitions. The chip has internal via holes for the source connections to ground. The drain and gate were bonded with 17.5 micron gold wires and length 200 µm. The reflection S-parameters of the transistor for -10 dBm input power, drain voltage 2 V and a drain-to-source current 10 mA.</div><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUILCRe-QZaQqKLM5k1-xEWq_K1PwF8r4kSuycBLY89nAbGzmLt61lUVBNH6H9dZBQIpdoasdrnNF3W6YVJI5zt60_K5xbtfTiZA4X8uaVzLPYSyaEhENqTyW61jlihzEZxRcJV2feOBQ/s1600/cosas.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUILCRe-QZaQqKLM5k1-xEWq_K1PwF8r4kSuycBLY89nAbGzmLt61lUVBNH6H9dZBQIpdoasdrnNF3W6YVJI5zt60_K5xbtfTiZA4X8uaVzLPYSyaEhENqTyW61jlihzEZxRcJV2feOBQ/s320/cosas.JPG" /></a></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>CPW probes</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The issues for testing the new sizes and frequencies in electronics are handling, fixturing and vision. Handling is a problem because human hands do not have the dexterity called for by the smallest electronic components and assemblies. Fixtures that are "hand-sized," with their larger contacts and thereby looser tolerances, generate parasitics that hinder good quality testing. As for vision, the human eye is not calibrated to easily distinguish discrete pieces as small as 0201 component, for example, with enough clarity to perform tests on them.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A rule of thumb is that repeatable measurements require 1 mil (0.0254 mm) contact placement accuracy at 10 GHz. A general solution to the previously mentioned test issues that enables an engineer to achieve this rule of thumb accuracy involves:</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li> CPW probes that provide an electrical reference plane at a precise point in space with precise planar contact, and are capable of quick and easy calibration.<br />
</li>
<li> The DUT holder must be secure, maneuverable and easy to load or unload.<br />
</li>
<li> The probe holding fixture should be rigid, repeatable and allow the flexible placement of probes.</li>
</ul><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The best CPW probes offer a wide range of planar contact styles, such as GSG, GS and SG. They offer a broad range of pitches from 75 µ to 2500 µ, controlled impedance, traceable calibration and relatively low cost. These probes are defined by bandwidth, e.g., 18 GHz, 40 GHz, up to 220 GHz and should be relatively low priced so that labs can afford to have probes with planar contacts precisely suited to their testing needs.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">CPW probe calibration is most efficient when there is a standard calibration kit available with standard calibration procedures. These procedures work best when they are internal to the test equipment and offer open-short-load-through (OSLT), line-reflect-match (LRM) and through-reflect-line (TRL) calibration, are software controlled with the capability of using SOLR, multiline (NIST) and other protocols.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>Probe stations/DUT holders</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A good probe station is flexible, portable, and low-cost and has options available that allow lab personnel to meet the specific testing demands of their customers' components and assemblies. The stations listed in the following paragraphs are capable of handling a wide range of applications, including, but not limited to testing semiconductor devices, microwave packages, MIC components and doing small sample failure analysis.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A basic, low-cost probe station that meets the needs of many engineers and scientists is capable of movement in the X, Y and Z axes. This grade of instrument will typically enable one inch of travel in the X and Y axes and 50 mils of vertical movement in the Z axis. The station will have a platen approximately 7" × 12" (178 mm × 305 mm) supporting a stage of approximately 2" × 2" (51 mm × 51 mm). A vacuum hold down secures components on the platen without placing stress in any plane. Optics on this type of probe station are in the 10x+ power range, and a fixed-intensity fluorescent ring illuminator provides adequate lighting for many applications.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">For the engineer or scientist who requires higher precision in a probe station that fits well in a personal workspace, the instrument of choice would be a compact manual probe station. This instrument, sometimes called a personal probe station, expands the features of the basic probe station. The stage size increases to 4.5 inches (114.3 mm) and travel in the X axis is 2.5 inches (63.5 mm) and in the Y axis is 4 inches (102 mm). An added feature of this class of probe station is travel up to 180° rotation in either direction. Standard optics have 7x-112x capability, and lighting is a fixed-intensity fluorescent ring illuminator.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A full-featured manual probe station offers the greatest range of capabilities to deal with the most demanding applications. This instrument gives the engineer or scientist a choice of a 6.5 inch (165 mm) or 8.5 inch (216 mm) stage. Added weight and size give this model more stability during tests. Movement in the X and Y axes is a full 6 inch (152.4 mm), 0.25 inches (6.4 mm) Z lift, and 180° rotation in the . Zoom optics have a 0.7x-4x objective lens providing magnification of 42x-270x for probe placement and DUT alignment with the standard 0.5x auxiliary lens. Removal of the auxiliary lens changes the range of magnification to 84x-540x for inspection and fine geometry probing. There is a 2x relay lens and a 0.5x or 1.0x (no lens) objective multiplier.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>Typical applications</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Many electronics devices can be tested in the different probe station models. Some of these applications fit one model better than another, but in general, the following devices can all be tested in a good quality probe station.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">First-order devices (do not require fixturing):</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li> Semiconductors — GaAs or any other advanced IC, II-VI or III-V devices for process control monitoring, RF performance or pulsed IV performance.<br />
</li>
<li> Surface-mount devices (SMD) — Micro BGAs, leadless carriers or leaded carriers such as a standard SOIC, upside down on either a conductive or non-conductive chuck.<br />
</li>
<li> SMD passive devices — Standard or custom calibration of hybrid couplers using a custom chuck.<br />
</li>
<li> MMIC packages — Capable of standard or custom calibration, often with a custom probe configuration and a custom device under test (DUT) holder.<br />
</li>
<li> Interconnect structures — Test high-performance PCBs for signal integrity, transition, impedance and parasitic elements.</li>
</ul><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Second-order devices (require fixturing with thin film adapter substrates):</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li>Transistors — Modeling and evaluation. </li>
<li>Diodes, single-port devices. </li>
<li>Packages that cannot be tested with standard CPW. </li>
</ul><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>Options</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">While a probe station usually comes equipped with standard features that are adequate for a majority of applications, sometimes it is necessary to add options that enable testing components with unusual requirements. Some of the options available for probe stations are:</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Manipulator/probe holder — these are available in different sizes, prices and features.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The basic model has a magnetic-mount positioner with dovetail slides for dc and general-purpose ac microprobing use, and features X, Y and Z travel. It usually comes with several needles that can be used to secure parts for test. This entry-level model has a magnetic mount.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">A slightly higher-priced model is available in which the slides are mounted on roller bearings for smoother X-Y travel and longer life. The engineer or scientist who buys this class of manipulator/probe holder can expect a 40 or 80 turns-per-inch positioner knob for precise placement of parts being tested, as well as somewhat greater travel capability in all axes than on the basic model. Knob planarity adjustment is another feature that is standard on this model. As with the basic model, a magnetic mount attaches it to the probe station.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Full-featured manipulator/holders have all the features listed in the previous models, but are bolt-mounted rather than magnet-mounted, giving them greater part holding strength and stability. They also offer greater movement in all axes.</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Upgraded microscope system;</div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><ul style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><li> vision-capture ready;<br />
</li>
<li> video-camera ready;<br />
</li>
<li> magnification range of 6.7x -168x with optional 1.5x objective;<br />
</li>
<li> thermal stage;<br />
</li>
<li> temperature control range of -5 °C to +125 °C;<br />
</li>
<li> vacuum DUT hold down; and<br />
</li>
<li> PCB holder — allows the testing of double-sided PCBs with bottom-side clearance.</li>
</ul><div style="text-align: justify;"></div><div class="sheader" style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><ul><li><i><b>Conclusion</b></i></li>
</ul></div><div style="text-align: justify;"></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Using CPW probes for precise measurements raises the bar. Having quality microwave transitions removes the uncertainty of how accurate the test data is because they improve the test contacts' integrity and the methods for micro-component measurements. CPW adapter substrates expand the applications that are possible. Microstrip devices become testable. A standardized calibration procedure assures that the measurement data is precise, repeatable and there is cross-facility data correlation.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Bibliografia: http://rfdesign.com/microwave_millimeter_tech/passive_components/radio_coplanar_waveguide_probes/</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-58437405010408671032010-06-27T20:21:00.002-04:302010-06-29T18:53:01.271-04:30Typical Matching Situations<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">It's relatively easy to design resistive terminations for waveguide and TEM structures that provide extremely wideband loads with Z=Zo of the transmission line. For situations where the loads must dissipate substantial power, thermal considerations come into play, and some form of conductive or convective cooling is necessary to prevent destruction of the load. In the extreme case, a long enough length of terminated lossy transmission line will present a high-power matched load to a transmission line of the same dimensions.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">The going gets tough in cases where impedance matching is required to narrow-band elements such as antennas or to devices with substantial reactance and resistance levels that are much lower (or higher) than typical transmission lines.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">An arbitrary impedance can, in principle, be matched at a single frequency by adding sufficient transmission line to move the impedance around the Smith chart until it lies on an admittance circle that passes through the center of the chart (g=20 millimhos or milliSiemens), then adding susceptance of the proper sign to move the combined admittance to the =0 point. The simplified Smith charts here show one of the two possible solutions for an arbitrary normalized impedance.</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVz_SO6KRkyPi2wJMOEGec4kv7hRcq_1VRGgW8JaIu3uzwdicy_5Iv-udFFEuRR0iHtL76UfNjjyC1rce3wW3oHjWrF_2x5Hd_QEbsfl2FJ3VswBbtFPIyjifoKUvZcPwxbwF2ZXvkAoo/s1600/asd.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVz_SO6KRkyPi2wJMOEGec4kv7hRcq_1VRGgW8JaIu3uzwdicy_5Iv-udFFEuRR0iHtL76UfNjjyC1rce3wW3oHjWrF_2x5Hd_QEbsfl2FJ3VswBbtFPIyjifoKUvZcPwxbwF2ZXvkAoo/s320/asd.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><span style="font-family: Georgia, 'Times New Roman', serif;">The other solution is</span><br />
<div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0oPhc9nC9DiR9gua7xIUtbhAG9UZiU2oFuLLaG7nnR8ckGvUJrP2KS69F8yCikXXGu1lpkrTzlkHYW3B-K8t1UTduLrnaO284D-qw_EL1aNstY9TXN194hg8v_os7pmhCmrBD3jPQmrI/s1600/Dibujo.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0oPhc9nC9DiR9gua7xIUtbhAG9UZiU2oFuLLaG7nnR8ckGvUJrP2KS69F8yCikXXGu1lpkrTzlkHYW3B-K8t1UTduLrnaO284D-qw_EL1aNstY9TXN194hg8v_os7pmhCmrBD3jPQmrI/s320/Dibujo.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Although inconvenient to realize in transmission line format, there are two other solutions that are obtained by rotating the arbitrary impedance until it is on the 50 circle, then adding the proper series reactance to bring the resulting impedance to the 50 point.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Recall that a useful expression for the impedance of a lossless transmission line of characteristic impedance Zo with an arbitrary load ZL and electrical length tita is</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; font-family: Georgia,"Times New Roman",serif; text-align: justify;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUGfktEX4pKAH7w_lZQsqk-UfotkL79Fmi3I5-QAG-5rDScNXFONG4Sc_TJIl1Zj8ixkC1nuH5rKTUPx4a5bXcEi1DDR_VXohdF7vbos7mfyxK5t9OcXZ7_kHjDQ7mY7-rjvVrzq8Q9dc/s1600/fisa.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUGfktEX4pKAH7w_lZQsqk-UfotkL79Fmi3I5-QAG-5rDScNXFONG4Sc_TJIl1Zj8ixkC1nuH5rKTUPx4a5bXcEi1DDR_VXohdF7vbos7mfyxK5t9OcXZ7_kHjDQ7mY7-rjvVrzq8Q9dc/s320/fisa.JPG" /></a></div><div style="font-family: Georgia,"Times New Roman",serif;">This can be used in connection with a spreadsheet or other calculation aid to keep track of the real and imaginary parts with varying frequency.<br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">But these are single-frequency solutions to the impedance matching problem. Because one of the major advantages of microwave usage is the opportunity to transmit substantial bandwidth, and because in practice one would hope to avoid a requirement for a unique circuit for each of the many frequencies in a typical 40% waveguide band, broadband solutions to the matching problem are valuable and sought-after.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Bibliografia: <a class="link" href="http://wsclick.infospace.com/clickserver/_iceUrlFlag=1?rawURL=http%3A%2F%2Fpuhep1.princeton.edu%2F%7Emcdonald%2Fexamples%2FEM%2Fleeson_ee246_099.pdf&0=&1=0&4=67.63.50.255&5=190.205.108.114&9=51c170219ba942428bf4ea5bc615cb01&10=1&11=iminentxml.intl.es&13=search&14=239138&15=main-title&17=3&18=2&19=0&20=0&21=3&22=6Er37UvxOP8%3D&40=2cUBmYW2XtOY4wgfQnnBLA%3D%3D&_IceUrl=true" id="weblink" jquery1277673563718="1691" target="_blank">http://puhep1.princeton.edu/</a><span class="foundOn"><span id="foundOnId"> </span></span></div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-46871825437607223052010-06-27T20:10:00.002-04:302010-06-29T18:52:35.386-04:30Impedance Matching<div style="text-align: justify;"><span style="font-size: large;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">Why Impedance Match?</span></b></span></div><div style="text-align: justify;"><br />
<span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">A question often asked by people new to the microwave field is, "what is so important about</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> impedance matching?" The answer is that this is one of the very few known and reliable</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> operating conditions (the others, which are harder to implement and are position-dependent,</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> and for which no power transfer is possible, are the short and open circuit).</span></span><br />
<br />
</div><div style="text-align: justify;"><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">Efficient power transfer is possible with other source and load impedances at a single</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> frequency, but the ability to measure and adjust to known conditions is too difficult to be</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> reliable. The other advantage of the matched load condition is that it uniquely removes the</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> requirement for a specific reference plane.</span></span><br />
<br />
</div><div style="text-align: justify;"><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">Also, the power-handling capacity of a transmission line is maximum when it is "flat", i.e.,</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> operating at low SWR. Lastly, it is important to be able to interconnect a number of</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> different components into a system, and the only way that can be done reliably and</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> predictably is by constraining the reflection coefficients of the various interfaces through</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> impedance matching. Multiple reflections can result in group delay variations that can</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> produce undesired intermodulation in broadband systems.</span></span><br />
<br />
</div><div style="text-align: justify;"><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">As we have seen, the S-parameter matrix is especially useful for transmission line and</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> waveguide situations, because the various parameters are defined for matched conditions.</span></span></div><div style="text-align: justify;"><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">This is extremely helpful in measurement of active devices, which may not be stable with</span></span><br />
<span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">source or load l l=1 characteristic of a short or open termination.</span></span><br />
<br />
</div><div style="text-align: justify;"><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">The greatest amount of engineering time is spent in searching for ways to provide efficient</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> impedance matching, especially to active circuit elements, so it pays to know some of the</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> many useful impedance-matching methods and their limitations. Microwave instruments</span></span><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"> for measurement of impedance by way of direct measur</span></span><span style="font-family: Georgia, 'Times New Roman', serif;">ement or S-parameters are among the most widely used tools of the microwave engineer</span>.</div><br />
<div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Publicado por Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: <a class="link" href="http://wsclick.infospace.com/clickserver/_iceUrlFlag=1?rawURL=http%3A%2F%2Fpuhep1.princeton.edu%2F%7Emcdonald%2Fexamples%2FEM%2Fleeson_ee246_099.pdf&0=&1=0&4=67.63.50.255&5=190.205.108.114&9=51c170219ba942428bf4ea5bc615cb01&10=1&11=iminentxml.intl.es&13=search&14=239138&15=main-title&17=3&18=2&19=0&20=0&21=3&22=6Er37UvxOP8%3D&40=2cUBmYW2XtOY4wgfQnnBLA%3D%3D&_IceUrl=true" id="weblink" jquery1277673563718="1691" target="_blank">http://puhep1.princeton.edu/</a></span>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-10385255299927975942010-06-27T19:56:00.002-04:302010-06-29T18:52:12.704-04:30Isolator (microwave)<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">An isolator is a two-port device that transmits microwave or radio frequency power in one direction only. It is used to shield equipment on its input side, from the effects of conditions on its output side; for example, to prevent a microwave source being detuned by a mismatched load.</span> </div><h2 style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;"><span class="mw-headline" id="Non-reciprocity">Non-reciprocity</span></span></h2><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">An isolator in a non-reciprocal device, with a non-symmetric scattering matrix. An ideal isolator transmits all the power entering port 1 to port 2, while absorbing all the power entering port 2, so that to within a phase-factor its S-matrix is</span></div><dl style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><dd><span style="font-size: small;"></span> </dd></dl><div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/math/0/8/5/085fbe555b903d7c1ef93d7bb6a0c77f.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="S = \begin{pmatrix} 0 & 0 \\ 1 & 0 \end{pmatrix}" border="0" class="tex" src="http://upload.wikimedia.org/math/0/8/5/085fbe555b903d7c1ef93d7bb6a0c77f.png" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">To achieve non-reciprocity, an isolator must necessarily incorporate a non-reciprocal material. At microwave frequencies this material is invariably a ferrite which is biased by a static magnetic field. The ferrite is positioned within the isolator such that the microwave signal presents it with a rotating magnetic field, with the rotation axis aligned with the direction of the static bias field. The behaviour of the ferrite depends on the sense of rotation with respect to the bias field, and hence is different for microwave signals travelling in opposite directions. Depending on the exact operating conditions, the signal travelling in one direction may either be phase-shifted, displaced from the ferrite or absorbed.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><h2 style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;"><span class="mw-headline" id="Types">Types</span></span><span style="font-size: small;"><b><span class="mw-headline" id="Resonance_absorption"> </span></b></span></h2><ul><li><span style="font-family: Georgia, 'Times New Roman', serif; font-size: small;"><b><span class="mw-headline" id="Resonance_absorption">Resonance absorption</span></b></span><br />
<h2 style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></h2></li>
</ul><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">In this type the ferrite absorbs energy from the microwave signal travelling in one direction. A suitable rotating magnetic field is found in the TE<sub>10</sub> mode of rectangular waveguide. The rotating field exists away from the centre-line of the broad wall, over the full height of the guide. However, to allow heat from the absorbed power to be conducted away, the ferrite does not usually extend from one broad-wall to the other, but is limited to a shallow strip on each face. For a given bias field, resonance absorption occurs over a fairly narrow frequency band, but since in practice the bias field is not perfectly uniform throughout the ferrite, the isolator functions over a somewhat wider band.</span><span style="font-size: small;"> </span><br />
<br />
<ul><li><b><span style="font-size: small;"><span class="mw-headline" id="Using_a_circulator">Using a circulator</span></span></b></li>
</ul><span style="font-size: small;"> A circulator is a non-reciprocal three- or four-port device, in which power entering any port is transmitted to the next port in rotation (only). So to within a phase-factor, the scattering matrix for a three-port circulator is</span></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/math/7/0/d/70d28854bf78f77ced4d4b401cdbfdaa.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="S = \begin{pmatrix} 0 & 0 & 1\\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix}" border="0" class="tex" src="http://upload.wikimedia.org/math/7/0/d/70d28854bf78f77ced4d4b401cdbfdaa.png" /></a></div><br />
<dl style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><dd><span style="font-size: small;"></span> </dd></dl><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">A two-port isolator is obtained simply by terminating one of the three ports with a matched load, which absorbs all the power entering it. The biassed ferrite is part of the circulator. The bias field is lower than that needed for resonance absorption, and so this type of isolator does not require such a heavy permanent magnet. Because the power is absorbed in an external load, cooling is less of a problem than with a resonance absorption isolator.</span></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="thumbcaption"><div class="separator" style="clear: both; text-align: center;"><a class="image" href="http://www.blogger.com/wiki/File:AisladorG.JPG" style="margin-left: 1em; margin-right: 1em;"><img alt="" class="thumbimage" height="165" src="http://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/AisladorG.JPG/220px-AisladorG.JPG" width="220" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: center;">An X band isolator consisting of a waveguide circulator with an external matched load on one port</div></div><div class="separator" style="clear: both; text-align: center;"><a class="image" href="http://www.blogger.com/wiki/File:AisladorC.JPG" style="margin-left: 1em; margin-right: 1em;"><img alt="" class="thumbimage" height="165" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/AisladorC.JPG/220px-AisladorC.JPG" width="220" /></a></div><div class="thumbcaption"><div style="text-align: center;"><span style="font-family: Georgia, 'Times New Roman', serif;">Two isolators each consisting of a coax </span>circulator<span style="font-family: Georgia, 'Times New Roman', serif;"> and a matched load</span></div></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Publicado por Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://en.wikipedia.org/wiki/Isolator_(microwave)</span></div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-84909572361670194532010-06-27T19:41:00.002-04:302010-06-29T18:51:43.461-04:30Types of S-parameters<span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">When we are talking about networks that can be described with S-parameters, we are usually talking about single-frequency networks. Receivers and mixers aren't referred to as having S-parameters, although you can certainly measure the reflection coefficients at each port and refer to these parameters as S-parameters. The trouble comes when you wish to describe the frequency-conversion properties, this is not possible using S-parameters.</span></span><br />
<br />
<ul><li><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"><b>Small signal S-parameters</b> are what we are talking about 99% of the time. By small signal, we mean that the signals have only linear effects on the network, small enough so that gain compression does not take place. For passive networks, small-signal is all you have to worry about, because they act linearly at any power level.</span></span></li>
</ul><ul><li><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"><b>Large signal S-parameters </b>are more complicated. In this case, the S-matrix will vary with input signal strength. Measuring and modeling large signal S-parameters will not be described on this page (perhaps we will get into that someday)</span></span></li>
</ul><ul><li><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"><b>Mixed-mode S-parameters</b> refer to a special case of analyzing balanced circuits. We're not going to get into that either!</span></span></li>
</ul><ul><li><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;"><b>Pulsed S-parameters</b> are measured on power devices so that an accurate representation is captured before the device heats up. This is a tricky measurement, and not something we're gonna tackle yet. </span></span></li>
</ul><br />
<div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><span style="font-size: small;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</span></div><span style="font-size: small;"><span style="font-family: Georgia, 'Times New Roman', serif;">Bibliografia: http://www.microwaves101.com/encyclopedia/sparameters.cfm</span></span> <span class="post-author vcard"> Publicado por </span>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-60526220676939189522010-06-27T19:30:00.002-04:302010-06-29T18:51:19.513-04:30S-parameters<div style="text-align: justify;"><span style="font-size: small;"><b><span style="font-family: Georgia, 'Times New Roman', serif;">History of S-parameters</span></b></span></div><div style="text-align: justify;"><span style="font-size: small;"><b><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></b><br style="font-family: Georgia,"Times New Roman",serif;" /><span style="font-family: Georgia, 'Times New Roman', serif;">S-parameters refer to the scattering matrix ("S" in S-parameters refers to scattering). The concept was first popularized around the time that Kaneyuke Kurokawa of Bell Labs wrote his 1965 IEEE article Power Waves and the Scattering Matrix. Check him out in our Microwaves101 Hall of Fame! It helped that during the 1960s, Hewlett Packard introduced the first microwave network analyzers. We'll also admit that there are several papers that predate Kurokawa's from the 1950s, one good early work was written by E. M. Matthews, Jr., of Sperry Gyroscope Company, titled The Use of Scattering Matrices in Microwave Circuits. Also, Robert Collin's textbook Field Theory of Guided Waves, published 1960, has a brief discussion on the Scattering matrix. Collin's book is extensively annotated, including an author index, which reads like a Who's Who of electromagnetic theory for the first half of the twentieth century.</span><br style="font-family: Georgia,"Times New Roman",serif;" /><br style="font-family: Georgia,"Times New Roman",serif;" /><b><span style="font-family: Georgia, 'Times New Roman', serif;">Introduction to S-parameters</span></b></span></div><div style="text-align: justify;"><span style="font-size: small;"><b><span style="font-family: Georgia, 'Times New Roman', serif;"> </span></b><br style="font-family: Georgia,"Times New Roman",serif;" /><span style="font-family: Georgia, 'Times New Roman', serif;">Before we get into the math, let's define a few things you need to know about S-parameters.</span><br style="font-family: Georgia,"Times New Roman",serif;" /><br style="font-family: Georgia,"Times New Roman",serif;" /><span style="font-family: Georgia, 'Times New Roman', serif;">The scattering matrix is a mathematical construct that quantifies how RF energy propagates through a multi-port network. The S-matrix is what allows us to accurately describe the properties of incredibly complicated networks as simple "black boxes". For an RF signal incident on one port, some fraction of the signal bounces back out of that port, some of it scatters and exits other ports (and is perhaps even amplified), and some of it disappears as heat or even electromagnetic radiation. The S-matrix for an N-port contains a N2 coefficients (S-parameters), each one representing a possible input-output path. </span><br style="font-family: Georgia,"Times New Roman",serif;" /><br style="font-family: Georgia,"Times New Roman",serif;" /><span style="font-family: Georgia, 'Times New Roman', serif;">S-parameters are complex (magnitude and angle) because both the magnitude and phase of the input signal are changed by the network. Quite often we refer to the magnitude onl, as it is of the most interest. Who cares how the signal phase is changed by an amplifier or attenuator? You mostly care about how much gain (or loss) you get. S-parameters are defined for a given frequency and system impedance, and vary as a function of frequency for any non-ideal network. </span><br style="font-family: Georgia,"Times New Roman",serif;" /><br style="font-family: Georgia,"Times New Roman",serif;" /><span style="font-family: Georgia, 'Times New Roman', serif;">S-parameters refer to RF "voltage out versus voltage in" in the most basic sense. S-parameters come in a matrix, with the number of rows and columns equal to the number of ports. For the S-parameter subscripts "ij", j is the port that is excited (the input port), and "i" is the output port. Thus S11 refers to the ratio of signal that reflects from port one for a signal incident on port one. Parameters along the diagonal of the S-matrix are referred to as reflection coefficients because they only refer to what happens at a single port, while off-diagonal S-parameters are referred to as transmission coefficients, because they refer to what happens from one port to another. Here are the S-matrices for one, two and three-port networks:</span></span></div><div style="text-align: justify;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEishCku3SSYzlasFl3UIf4Bv3em66zM6WLA_XEQBQrOBxWkOSX3uKdYauJejkj3Z8bk-HWGqesQTgl_Jvs3iUV2QjUv7Ycj5mFOqqaUlTngCRFym22wzW-wiAEbI6V__dQUtDv-JwhYeR4/s1600/matrices.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEishCku3SSYzlasFl3UIf4Bv3em66zM6WLA_XEQBQrOBxWkOSX3uKdYauJejkj3Z8bk-HWGqesQTgl_Jvs3iUV2QjUv7Ycj5mFOqqaUlTngCRFym22wzW-wiAEbI6V__dQUtDv-JwhYeR4/s320/matrices.jpg" /></a></div><div style="text-align: justify;"></div><div style="text-align: justify;"><span style="font-family: Georgia, 'Times New Roman', serif;">Note that each S-parameter is a vector, so if actual data were presented in matrix format, a magnitude and phase angle would be presented for each Sij.</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">The input and output reflection coefficients of networks (such as S11 and S22) can be plotted on the Smith chart. Transmission coefficients (S21 and S12) are usually not plotted on the Smith chart.</span><br />
<br />
<b><span style="font-family: Georgia, 'Times New Roman', serif;">Definition of S-parameters</span></b></div><div style="text-align: justify;"><br />
<span style="font-family: Georgia, 'Times New Roman', serif;">S-parameters describe the response of an N-port network to voltage signals at each port. The first number in the subscript refers to the responding port, while the second number refers to the incident port. Thus S21 means the response at port 2 due to a signal at port 1. The most common "N-port" in microwaves are one-ports and two-ports, three-port network S-parameters are easy to model with software such as Agilent ADS, but the three-port S-parameter measurements are extremely difficult to perform with accuracy. Measure S-parameters are available from vendors for amplifiers, but we've never seen a vendor offer true three-port S-parameters for a even a simple SPDT switch (a three-port network).</span><br />
<br />
<span style="font-family: Georgia, 'Times New Roman', serif;">Let's examine a two-port network. The incident voltage at each port is denoted by "a", while the voltage leaving a port is denoted by "b". Don't get all hung up on how two voltages can occur at the same node, think of them as traveling in opposite directions!</span></div><div style="text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcf1nb9UHZqVZoJAS9SoC_ApvcdL5RHmmDQdUqNYak20_PIpfXTSpgUyCN7I30prhjz54oUBXcdw4Z6vyHJNK8Nflx4Yhom6_4SOPMaCVmKVexbM8pfxWreXY06GmHgKqx1e_qiOkOL8A/s1600/diagram1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcf1nb9UHZqVZoJAS9SoC_ApvcdL5RHmmDQdUqNYak20_PIpfXTSpgUyCN7I30prhjz54oUBXcdw4Z6vyHJNK8Nflx4Yhom6_4SOPMaCVmKVexbM8pfxWreXY06GmHgKqx1e_qiOkOL8A/s320/diagram1.jpg" /></a></div><div style="text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">If we assume that each port is terminated in impedance Z0, we can define the four S-parameters of the 2-port as:</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNT0XBjiNEVNyVXl6EHzVUtGKglgKMUZgFAAkraKVn0imxS9yV5Ih68GIUU3y6JvQUufgf3KNK3nRMvAn787fZJgUKdrsuQUSspbCks_n2NArwma2mIH1hWocigTv6oCdnbtlm4SZLtKw/s1600/equations1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNT0XBjiNEVNyVXl6EHzVUtGKglgKMUZgFAAkraKVn0imxS9yV5Ih68GIUU3y6JvQUufgf3KNK3nRMvAn787fZJgUKdrsuQUSspbCks_n2NArwma2mIH1hWocigTv6oCdnbtlm4SZLtKw/s320/equations1.jpg" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">There's a missing step to this derivation, which was pointed out by Alex (thanks!) You'll find the complete derivation on Wikipedia, we'll update this page soon.<br />
<br />
See how the subscript neatly follows the parameters in the ratio (S11=b1/a1, etc...)? Here's the matrix algebraic representation of 2-port S-parameters:</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYfYP1bBkif63pEVH82AGQYXw-91lVTAMQtnxWpNiztcg4Eoulx860_FztZjuZcD5BrQPVV0rd22tzC5WZ53Z4IjFuWLoNkM5rswJD5aE7Q27vWLAnU9d_0K1XCOU38QEbrx21vCpRL7A/s1600/equations2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYfYP1bBkif63pEVH82AGQYXw-91lVTAMQtnxWpNiztcg4Eoulx860_FztZjuZcD5BrQPVV0rd22tzC5WZ53Z4IjFuWLoNkM5rswJD5aE7Q27vWLAnU9d_0K1XCOU38QEbrx21vCpRL7A/s320/equations2.jpg" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">If we want to measure S11, we inject a signal at port one and measure its reflected signal. In this case, no signal is injected into port 2, so a2=0; during all laboratory S-parameter measurements, we only inject one signal at a time. If we want to measure S21, we inject a signal at port 1, and measure the resulting signal exiting port 2. For S12 we inject a signal into port 2, and measure the signal leaving port 1, and for S22 we inject a signal at port 2 and measure its reflected signal.<br />
<br />
Did we mention that all of the a and b measurements are vectors? It isn't always necessary to keep track of the angle of the S-parameters, but vector S-parameters are a much more powerful tool than magnitude-only S-parameters, and the math is simple enough either way.<br />
<br />
S-parameter magnitudes are presented in one of two ways, linear magnitude or decibels (dB). Because S-parameters are a voltage ratio, the formula for decibels in this case is <br />
<br />
Sij(dB)=20*log[Sij(magnitude)]<br />
<br />
Remember that power ratios are expressed as 10xlog(whatever). Voltage ratios are 20xlog(whatever), because power is proportional to voltage squared.<br />
<br />
The angle of a vector S-parameter is almost always presented in degrees (but of course, radians are possible).</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Publicado por Jahir Alonzo Linares Mora CI: 19769430 CRF</b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><b>Bibliografia: http://www.microwaves101.com/encyclopedia/sparameters.cfm</b></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0tag:blogger.com,1999:blog-5526057606007105240.post-28234742398734986492010-06-27T19:15:00.002-04:302010-06-29T18:50:57.178-04:30MPC y HMIC<div class="post-body entry-content"><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">En 1951, aparece la tecnología MPC, cuyo significado se puede traducir por circuitos impresos de microondas. Se basaba en la tecnología stripline, que destaca por una línea de configuración planar y un cable coaxial modificado. Destacaban porque eran ligeros, de fácil fabricación y su producción tenía un coste barato. Su sustrato estaba hecho de teflón (PTFE).<br />
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Las diferentes aplicaciones de la tecnología se muestran a continuación:</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/c/cf/Aplicaciones_de_la_tecnolog%C3%ADa_MPC.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="87" src="http://upload.wikimedia.org/wikipedia/commons/c/cf/Aplicaciones_de_la_tecnolog%C3%ADa_MPC.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">En 1952, se crea la tecnología Microstrip, y con ella, se desarrolla otra tecnología, la HMIC, circuitos integrados de microondas híbridos. Las claves fueron el desarrollo de los transistores FET frente a los BJT, ya que eran más pequeños, se podía trabajar a más alta frecuencia e introducían menos ruido. El sustrato estaba compuesto de alúmina. Un punto a destacar es que esta tecnología posee una capa de metalización de sus conductores, líneas de transmisión y componentes discretos, como son resistencias, condensadores, inductores… pegadas al sustrato.<br />
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Las propiedades que destacan de la tecnología HMIC se pueden resumir en la siguiente lista:</div><ul><li style="font-family: Georgia,"Times New Roman",serif;">Creación de la tecnología a una escala muy pequeña</li>
<li style="font-family: Georgia,"Times New Roman",serif;">Sustratos de alta permitividad</li>
<li style="font-family: Georgia,"Times New Roman",serif;">Gran nivel de integración.</li>
<li><span style="font-family: Georgia, 'Times New Roman', serif;">Producción a gran escala. </span></li>
</ul><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;">Tres son los procesos que destacan a la hora de la fabricación de la tecnología HMIC:<br />
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<b>Fotograbado o Thin-Film:</b> Producción en cadena y espectro ancho.<br />
<b>Serigrafía o Thick-Film: </b>Fabricación barata y cubre el espectro de microondas.<br />
<b>Cerámica cocida a baja temperatura o Low-Temperature Cofired Ceramic (LTCC): </b>Multicapa, elevada integración y flexibilidad de diseño. <br />
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Las claves por las cuales esta tecnología se superpuso a las tecnologías de su época fue debido al buen comportamiento que tenía a muy altas frecuencias y la estandarización de los procesos de fabricación le dieron a esta tecnología una ventaja sobre las demás.</div><div style="font-family: Georgia,"Times New Roman",serif; text-align: justify;"></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/8/83/HMIC._M%C3%B3dulo_sintetizador_de_12_GHz.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="223" src="http://upload.wikimedia.org/wikipedia/commons/8/83/HMIC._M%C3%B3dulo_sintetizador_de_12_GHz.jpg" width="320" /></a></div><div style="font-family: Georgia,"Times New Roman",serif;"><br />
</div><div style="font-family: Georgia,"Times New Roman",serif;">Publicado por: Jahir Alonzo Linares Mora C.I: 19769430 CRF</div><div style="font-family: Georgia,"Times New Roman",serif;">Bibliografía: http://es.wikipedia.org/wiki/Circuito_integrado_de_microondas</div></div>Tecnología en Telecomunicaciones - conocimientos.com.vehttp://www.blogger.com/profile/13517798918797491823noreply@blogger.com0