一种具有温度补偿的GaN功放线性化器

李飞锐，郑宝辉，王雷，陈冠军，刘士奇

摘要：为改善氮化镓固态功率放大器的非线性失真，利用模拟预失真线性化技术，设计出一款新型线性化器，将其用于氮化镓固态功率放大器的线性化驱动模块，并增加温度补偿方案。通过使用多管级联方式增强二极管非线性特性，并对二极管管座电路进行优化设计，将射频接地与直流接地分离，使用电磁仿真软件对线性化器进行仿真验证。仿真结果表明，实物加工后进行测试，可实现增益幅度补偿范围0.9～7.6 dB，相位补偿范围9°～40°，对比相关文献，分别提高了1.2 dB和12°。线性化驱动模块与目标放大器级联测试，在29 GHz饱和功率回退7 dB时，三阶互调改善7.07 dB，性能优异。所设计的预失真器可改善功率放大器的非线性特性，提高卫星通信系统性能，对卫星通信系统具有重要意义。

关键词：微波技术;GaN功放;模拟预失真;温度补偿;线性化器

中图分类号：TN927+.2文献标识码：ADOI： 10.7535/hbgykj.2021yx06003

A GaN power amplifier linearizer with temperature compensation

LI Feirui，ZHENG Baohui，WANG Lei，CHEN Guanjun，LIU Shiqi

（The 54th Research Institute of CETC，Shijiazhuang，Hebei 050081，China）

Abstract：In order to improve the nonlinear distortion of GaN solid-state power amplifier，a new linearizer was designed by using analog predistortion linearization technology，which was used in the linearization driving module of GaN solid-state power amplifier，and a temperature compensation scheme was added.The nonlinear characteristics of diode were enhanced by using multi transistor cascade，and the diode socket circuit was optimized and designed to separate RF grounding from DC grounding.The linearizer was simulated and verified by electromagnetic simulation software.The simulation results show that the gain amplitude compensation range is 0.9～7.6 dB and the phase compensation range is 9°～40° after processing and testing.Compared with the relevant literature，it is increased by 1.2 dB and 12° respectively.The linearized drive module is tested in cascade with the target amplifier，when the 29 GHz saturated power retreats by 7 dB，the third-order intermodulation is improved by 7.07 dB and the performance is excellent.The designed predistorter can improve the nonlinear characteristics of power amplifier and improve the performance of satellite communication system，which is of great significance to satellite communication system.

Keywords：microwave technology;gallium nitride power amplifier;analog predistortion;temperature compensation;linearizer

衛星通信产业迅速发展，频谱资源愈发有限，高效且复杂的调制技术能够充分利用有限的资源，但也对功率放大器（简称“功放”）的线性度提出了较高的要求[1-2]。为达到卫星通信所需的线性度要求，功放通常多采取功率回退法，通过降低工作效率以提升线性度，同时也会造成功放的体积和功耗增大。为解决这一难题，众多线性化技术由此诞生，其中模拟预失真技术具有结构简单、成本低、稳定性好的特点，适用于卫星通信应用场景[3-4]。目前，卫星通信系统中氮化镓（GaN）固态功放芯片已经逐渐取代砷化镓（GaAs）固态功放芯片，使功放既能满足大功率低功耗需求又可以满足小型化要求，但GaN固态功放的高线性化实现难度很大，模拟预失真技术在GaN固态功放中较难实现。……