Chirp子脉冲频率步进信号的距离副瓣抑制

Range sidelobe suppression of stepped Chirp waveforms

分析了Chirp子脉冲频率步进信号的高分辨一维距离像距离副瓣产生的原因及传统加权处理带来的不良影响,提出一种易于工程实现的Chirp子脉冲非线性频率步进信号。通过对同步进载频的子脉冲相干积累改变频谱的能量分布,实现不同窗函数的模拟加权并还原成线性频率步进信号,在抑制距离副瓣的同时提高输出高分辨一维距离像信噪比。仿真结果表明,该方法抗噪性能好,与传统加权处理相比,在主副比基本相同的情况下,输出一维距离像信噪比有所提高。

This paper analyses the root cause of range sidelobe occurring and undesirable attributes associated with conventional weighting technology for stepped chirp waveforms,then formulates a new easily realizable non-linear stepped chirp waveform that distributes energy non-uniformly over the desired synthetic frequency band using coherent integration. It will improve the signal-to-noise ratio（SNR）while greatly suppressing the range sidelobes. Simulation result shows that under almost the same range sidelobe suppression level, the SNR of range profile is improved compared with conventional weighting technology.