高效宽带包络跟踪系统电路性能优化及非线性行为校正  

Circuits Optimization and System Linearization for High Efficiency and Wideband Envelope Tracking Architecture

作　　者：曹韬[1] 刘友江[1] 杨春[1] 周劼[1] CAO Tao;LIU Youjiang;YANG Chun;ZHOU Jie(Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院电子工程研究所,绵阳621900

出　　处：《电子与信息学报》2020年第3期787-794,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61601425)~~

摘　　要：为改善包络跟踪(ET)发射机带宽、效率、线性度等指标,需优化其关键电路性能并校正系统非线性行为。针对该问题,该文构建电源调制器等效模型,推导其效率极值并阐述效率优化方法;引入频率补偿网络来提升电路带宽及线性性能;基于系统非线性行为特征,提出包络增强型数字预失真模型及线性化方案;设计实际电路并搭建包络跟踪系统。对于S频段5/10/20 MHz带宽6.7 dB峰均比测试信号,该系统功放平均效率分别为61%,54%, 44%,且矢量幅度误差(EVM)均优于1%,具有较好的带宽、效率、线性度等性能,验证了电路优化方法及非线性行为校正方案的可行性。To improve bandwidth, efficiency and linearity of Envelope Tracking(ET) architecture, it is necessary to optimize the performance of envelope supply modulator and linearize nonlinear behavior of the ET system. The optimization procedure of the supply modulator is proposed based on the equivalent circuit model.The frequency compensation network is used to improve the bandwidth and linearity of the modulator circuit.An envelope enhanced memory polynomial digital pre-distortion model is introduced to address the nonlinear distortion of the ET system. The practical circuit mentioned above is fabricated and the overall experimental system is set up. Measurement results show that the ET PA at S-band obtains measured efficiency 61%, 54%,44% and Error Vector Magnitude(EVM) 1% for 6.7 dB PAPR signals with 5 MHz/10 MHz/20 MHz modulation bandwidths, respectively. The ET system exhibits competitive bandwidth, efficiency and linearity,which verifies the proposed optimization and linearization methodology.

关 键 词：包络调制器 包络跟踪 数字预失真 高效率 

分 类 号：TN919[电子电信—通信与信息系统]