complex的博客

Look at the chips in the Palm Pre.              ...

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转载一篇。 *** 手机射频系统有三个主要零组件，收发器（Transceivers）、功率放大器（Power Amplifier，下简称PA）和天线开关，有时PA包含在前端模块（Front-End-Module，简称FEM）。2G时代的射频系统只占大约1.5美元的成本，3G时代则占大约6-8美元的成本，4G时代则占大约8-10美元的成本，也是手机升级换代成本增加最多的部分。    收发器是手机平台的一部分，通常提供手机基频的厂家都要提供收发器，两者基本上一一对应的关系。诺基亚是个例外，它采用德州仪器的基频，但是却采用意法半导体或英飞凌提供的收发器。不过现在...

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  看看我已经无聊到了什么地步。整整两天，一个人霸占了整个办公室，做一些很没劲的事情：整理整理读过的书，翻翻硬盘上的资料......一个人的周末，下着雨不能打球，婷儿还没有回来，我还能做什么呢？挺无聊的。 于是，决定梳理一下自己这几年做MMIC/RFIC的知识，画张图直观化，看看自己到底掌握了多少，还有什么欠缺。图是用Smart Draw画的，从半导体材料-->器件-->工艺-->电路设计-->测试封装，为了高度概括，所以只能写一些关键词。也许还有遗漏，不过看上去已经挺庞大的了。在IMECAS读书这几年，尽管没有什么成...

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1. GaAs 半导体材料可以分为元素半导体和化合物半导体两大类，元素半导体指硅、锗单一元素形成的半导体，化合物指砷化镓、磷化铟等化合物形成的半导体。砷化镓的电子迁移速率比硅高5.7 倍，非常适合用于高频电路。砷化镓组件在高频、高功率、高效率、低噪声指数的电气特性均远超过硅组件，空乏型砷化镓场效应晶体管(MESFET)或高电子迁移率晶体管(HEMT/PHEMT)，在3 V 电压操作下可以有80%的功率附加效率(PAE: Power Added Efficiency)，非常适用于高层(high tier)的无线通讯中长距离、长通信时间的需求。 砷化镓元件因电子迁移率比硅高很...

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《论语·为政》——子曰：“学而不思则罔，思而不学则殆”。 其意思是：学习而不思考，人会被知识的表象所蒙蔽；思考而不学习，则会因为疑惑而更加危险。最近一段时间埋头苦读，对于这两句话有了更加深刻的理解。每个人或多或少都会患有这两种毛病，从我身边就能找到很多活生生的例证。当然，比起不学也不思来，这两种毛病只能算得上瑕疵。我自己的毛病，更多的是“学而不思”。无论在高中，大学还是研究生中，你都可以发现很多像我这样比较勤奋刻苦的人，但这一类人往往会“劳而无功”，所取得的成绩与付出的辛劳严重不成比例；当然也会发...

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Chapter 8: Test Questions:  1. What else should be provided at the side of the chips, as well as dc bias pads, to aid decoupling? 2. How much current can a typical probe needle feed onto the chip? 3. What does RFOW stand for, and what are its advantages? 4. How many contacts does an RFOW probe have, and what are they for? 5. What does the calibration do? Answers:  1. A dc pad connected to a through-substrate via, preferably one for each bias supply. 2. 0.5A. 3. Radio Frequenc...

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Chapter 7: Processing Technology Questions:  1. What is meant by the word monolithic in the MMIC acronym? 2. What is important about the structure of the substrate material? 3. How are the wafers produced? 4. Why is it useful to use a low-conductivity, semi-insulating substrate material? 5. How is the conductivity of a semiconductor increased for the active layers in the transistors? 6. What are the different ways to create an active layer? 7. What are the two common photoresist pro...

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hapter 6: Layout Questions:  1. MMIC layout data files are built up from lines or polygons? 2. What does hierarchy mean in the context of MMIC layout? 3. Does the MMIC designer construct the layers within the transistors? 4. What is the consequence if critical errors are not spotted before the masks are manufactured? 5. What determines the layout rules? Give two examples. What is the general approach for laying out an MMIC? 6. What do DRC, LVS and ERC stand for? 7. What is the proce...

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Chapter 5: Design Questions:  1. Which MMIC transistor technology has an operating frequency down to dc? 2. Which MMIC transistor technology is most suited to low-noise mm-wave applications? 3. Which MMIC transistor technology can operate over 100GHz? 4. What is a good figure for the gain per stage in a multistage amplifier MMIC? 5. What range of input match is reasonable to expect for a 10GHz MMIC? 6. What are the dc bias pads usually placed, and what characteristics of their placement are...

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Chapter 4: Simulation and Component Models Questions:  1. What are the limitations of s-parameter representation of MMIC component elements? 2. How are the individual MMIC components characterized? 3. What is the "lumped-element" approximation? 4. How do the parasitic elements differ from the prime element in an equivalent circuit model? 5. What extra requirements does nonlinear simulation place on the models? 6. Why would an MMIC use 3D EM simulation? 7. What effect will placing a ...

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今天开始，推出一个系列的“MMIC问答”，基本包括MMIC设计的方方面面。当然，这个高度不是我所能达到的，我只是做做打字员，借花献佛。再次强烈推荐Steve Marsh著《Practical MMIC Design》。 *** Chapter 2: Component Technology and Foundry Choice Questions:  1. What characteristics of the semiconductors material determine the frequency range over which it can be used for producing MMICs? 2. Which semiconductor substrate materials exhibit a wide bandgap, making them suitable for high-output power app...

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The International Microwave Symposium (IMS), June 7-12 at the Boston Convention & Exhibition Center in Boston, MA, will feature 430 technical presentations in over 90 sessions, representing the latest research in the field from around the world and organized in four technical tracks: Microwave Systems; Active Components; Passive Components; and Microwave Modeling. “The topics of the program’s diverse technical presentations range from components to systems and feature emerging compon...

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WOBURN, Mass.--(BUSINESS WIRE)--Jun. 2, 2009-- Skyworks Solutions, Inc. (NASDAQ:SWKS), an innovator of high reliability analog and mixed signal semiconductors enabling a broad range of end markets, today announced its acquisition of Axiom Microdevices, the world's only volume supplier of CMOS-based power amplifiers for mobile phones. ...

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From: compoundsemiconductor.net Partnerships with NREL on concentrated photovoltaics, and a variety of customers on high power RF are set to bring new business to the company's Greensboro fabs. GaAs chip pioneer RF Micro Devices is readying two significant departures from its traditional business model, as it enters the foundry services and solar cell markets. The US National Renewable Energy Laboratory's John Geisz holds an inverted metamorphic GaAs-based solar cell that claimed the ...

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