【作者】 金博识；

【导师】 李乐伟； 吴群；

【作者基本信息】 哈尔滨工业大学 ， 微电子学与固体电子学， 2011， 博士

【摘要】 随着移动通信系统的迅速发展，要求射频前端模块具有更高的集成度，更低的成本，同时能够更加的适应未来移动通信系统的高带宽要求。由于CMOS(Complementary Metal Oxide-Semiconductor)工艺具有较低的成本，并且可以很好的实现普通的射频小信号器件和逻辑控制电路，因此被看做实现单芯片射频模块的最有前途的工艺解决方案之一。但是由于CMOS晶体管本身较低的击穿电压，导性基片和无过孔工艺等限制，使得目前还无法设计实用的射频功率放大器(以下简称功放)。因此，本文针对CMOS工艺的特点，开展了对射频CMOS功放结构和线性度加强技术的研究，设计实现了全集成的射频CMOS功放。对于最终实现全集成的射频前端模块具有重大的现实意义。首先，根据CMOS工艺的特点，提出了适台大信号工作条件下的CMOS功率元结构和等效分忻模型。通过仿真优化分忻，得出了功率元的最优单指栅宽和总栅宽等设计参数，并使用了0．18 um标准的CMOS工艺流片验证，测试结果表明，该功率元结构具有较低的损耗并与仿真模型符台较好，具有良好的可扩展性，为进一步设计高功率的cMC)s功放提供了良好的基础。其次，利用传输线的奇偶理论设计了小尺寸，低损耗和高工作带宽的在片转换器。针对CMOS功率放大器常常采用差分结构的特点，使用传输线的奇偶理论分忻了转换器的带宽和损耗等性能，提出了通过在输入和输出端加入集总电容可以降低转换器的损耗并大幅减小转换器尺寸，通过实际的加工流片测试，验证了该设计方法的正确性。第三，利用所提出的功率元结构和转换器模型，以m—WiMAx(MobileWorldwide-InteropeEabilit3’fbrMk：rOVvraveAccess)为实际应用背景设计了超宽带线性CMOS功放。通过输出阻抗匹配电路对功放带宽性能影响的分忻，提出了通过将转换器寄生参数综台考虑到输出阻抗匹配电路内以降低匹配阻抗随频率变化的响应，从而增加了功放的工作带宽。以TSM(：0．18 um CMOS工艺为基础，首次在国内设计了全集成的宽带射频功放，该功放所有输入和输出匹配均实现了在片集成，芯片全部尺寸仅为1．2 mm×2 mm，实际测试结果表明，该功放的工作带宽达到1 GHz。第四，使用模拟预失真技术加强了CMOS功放的线性度。利用CMOS晶体管跨导具有较强的非线性的特点，在对其三次谐波分量特性分忻的基础上，通过调整驱动级和功率级的栅极偏置，使得他们在优化功率范围内的三次跨导分量相互抵消，提高了线性度。使用TSM(：0．1 8 um CMOS工艺流片验证理论分忻，测试结果表明，在24—2’7dBm的输出功率范围内，m—WiMAx功率谱改进了8 dB以上。最后，利用输出匹配电容对转换器工作频点影响的特性，设计了可工作于2．5 GHz和3．5 GHz的双频段射频CMOS功率放大器。通过开关切换在不同频点下的匹配电容值，实现了转换器的双频点的匹配；同时，通过对转换器级问和输入匹配的优化设计，保证了功放在双频点工作状态下的性能。使用Dorlgbu0．13um CMOS工艺流片做仿真验证分忻和加工，实际测试结果表明，在2．5 GHz和3．5 GHz下的输出功率分别达到了29 dBm和28．5 dBm，与仿真分忻结果符台的较好。本文的研究成果在于利用目前标准的CMOS工艺设计制造了全集成的线性射频功率放大器，同时在设计高线性度，高带宽和减小芯片面积方面展开了更为深入的研究，克服解决了传统的由于CMOS工艺条件限制所造成的功放设计难题，对最终实现以CMOS工艺为基础的高性能，低成本全集成射频前端模块具有重大的现实意义。更多还原

【Abstract】 With the development of mobile communication systmen，it requires the radiofrquency(RF)front—end module(FEM)with high performance，low cost and widebandwidth．Due to the low cost of CMOS(Complementary Metal OxideSemiconductor)process and easy implementation on small RF signal devices andlogic control circuits，it is recognized as one of the promising single chip FEMsolutions．However，currently，it is still difficult to implement the reliable RF poweramplifier(PA)because CMOS transistor has the low breakdown volatge，conductivesubstrate and no vias．In this research，the configuration of CMOS PA andlinearization techniques are studied based on the charisteritcs of CMOS process，andthe fully—integrated CMOS PAs are implemented．It has big sense on implementationsof single chip CMOS FEM finally．Firstly，the structure of power cell for large signal operation and its analyzedmodel are proposed．The optimum single finger width and total width of power cellare concluded based on the optimization，and they are vwerificated with standard0．1 8 um CMOS process．The measured results reveal that the structure has the lowcost and confirms well with the proposed model，and is also scalable．This workprovides solide base for high power PA design．Secondly，the on—chip comnpact and low loss transformer is proposed with theeven mode and odd mode theory．The bandwidth and loss of transformer are analyzedwith the even mode and odd mode theory for difl~neratial confignaration of CMOSPA，the method that adding lumped capacitors at the input and output is proposed toreduce the loss and size．The analysis is verificated with the fabrication．Thirdly，based on the proposed power cell and transformer，the wideband CMOSPA is designed as the background of m—WiMAX《Mobile Worldwide Interoperabmtyfor Microwave Access)．The wide bandwidth is obtained by absorbing the parasiticparameters of output matching circuit into the load impedance matching to reduce thefrequency response．The fully—integrated PA is implemented in TSMC 0．1 8 umCMOS process．All of the input and output matching components are integated onchip，and the total size of chip is only 1．2 mm×2 mm．The measurment reveals that ithas 1 GHz bandwidth Fourthly，The lineairty of CMOS PA is enhanced with the analog pre—distortiontechnique．The strong nonlinear transconductance of CMOS transistor and its thordharmonic are analyzed．The third harmonics genertaed by power stage and driverstage are canclled within the specific output power，thus the lineairty is enhanced．The theoretical analysis is verificated with TSMC 0．18 um CMOS process．Themeasurements reveal that the m—WiMAX spectrum can be improved by 8 dB．Finally．the 2．5一GHz and 3．5-GHz dual band CMOS PA is designed with thecharacteristic that output matching capacitor has big impacts on operation frequencyband．The dual band matching is achieved by switching capacitor values；theinter—stage and input matching are also optimized to guarantee the performance．Theanalysis is verificated with Dongbu 0．13um CMOS process．The measurementsreveal that the PA can achieve 29 dBm and 28．5 dBm at 2．5 GHz and 3．5 GHz．respectively，and confirms well with the simulation．his work utilized the current standard CMOS process design the high powerfully—integrated CMOS PA，and studies deeeply on high linearity，wide bandwidthand chip size reduction．The challenges are overcome due to the restrictions ofCMOS process and it has big sense on implementation of high performance and lowcost RF CMoS FEM．更多还原