中国科学院大学学报2024，Vol.41Issue(4)：524-532,9.DOI:10.7523/j.ucas.2022.079
SAR激励信号正交调制幅相不平衡预失真校正方法
A predistortion correction method for quadrature modulation amplitude and phase imbalance of SAR excitation signal
摘要
Abstract
Analog I/Q modulation technology is one of the most commonly used and important technical means in broadband synthetic aperture radar(SAR)exciter design.With the increasing instantaneous bandwidth of radar system,the amplitude-phase consistency of analog I/Q modulation can not be completely guaranteed by the symmetrical characteristics of devices,and the spurious distortion caused by the IQ imbalance in broadband radar transmission system will deteriorate progressively.This paper proposes a digital predistortion method which can extract all amplitude-phase errors on the whole transmission channel,mainly including IQ imbalance,by modeling the system error and building a test system,map the amplitude-phase errors to the IQ branch of digital baseband signal output,and compensate the amplitude-phase distortion of the transmission channel.Finally,combined with the actual radar transmitting system,the distortion of the whole transmitting link is corrected by using the predistortion method.The test results before and after correction are given,demonstrating the effectiveness of the method.关键词
合成孔径雷达/正交调制/宽带/IQ不平衡/幅相误差Key words
SAR/I/Q modulation/wideband/IQ imbalance/amplitude-phase errors分类
信息技术与安全科学引用本文复制引用
贾颖新,王岩飞..SAR激励信号正交调制幅相不平衡预失真校正方法[J].中国科学院大学学报,2024,41(4):524-532,9.基金项目
国家重点研发计划(2017YFB0503001)资助 （2017YFB0503001）
