星载气象雷达功放非线性对超低副瓣脉冲压缩信号的影响及消除  

Power Amplifier Predistortion on Pulse Compression with Very Low Sidelobes for Spaceborne Weather Radar

作　　者：朱迪[1] 董晓龙[1] 

机构地区：[1]中国科学院空间科学与应用研究中心,北京100190

出　　处：《数据采集与处理》2009年第6期825-829,共5页Journal of Data Acquisition and Processing

摘　　要：为在强海面回波影响下测量反射较弱的雨云,星载气象雷达要求脉冲压缩的主副瓣功率比高于60 dB。因此超低副瓣脉冲压缩成为星载气象雷达的核心技术之一。超低副瓣的实现对线性度要求很高,星载雷达为保证发射机的功率和效率,功放多工作于近饱和区,造成副瓣电平恶化。本文分析了功放非线性对超低副瓣脉冲压缩信号的影响,基于射频功率放大器、矢量信号发生仪和矢量信号分析仪实现了功放数字预失真算法,并利用松弛迭代法提高了迭代收敛速度。在保证星载气象雷达超低副瓣的前提下提高了发射机的功效。The pulse compression with very low sidelobes is one of challenges in the design of the spaceborne weather radar. To detect the weak echoes of clouds occurred near the strong echoes of the sea surface, the sidelobe performance below-60 dB is needed in the pulse compression system. To achieve such low sidelobes, the high linearity is required in the radar system. But in spaceborne radar system, the transmitter often works at saturation point to obtain the high output power and the efficiency. So a successive overrelaxation （SOR） iterative method of the digital predistortion is used to ensure the low sidelobe performance, the high output power and the fast iterative speed. A test system based on RFPA, electronic signal generator and vector signal analyzer is used to verify and optimize the predistortion algorithm.

关 键 词：脉冲压缩 超低副瓣 非线性 预失真 松弛迭代法 星载气象雷达 

分 类 号：TP7[自动化与计算机技术—检测技术与自动化装置]