基于NLFM的超低旁瓣脉冲压缩方法研究  

An Ultra-Low Sidelobe Pulse Compression Method Based on Nonlinear Frequency Modulation Signal

作　　者：刘萍[1] 邹林[1] 周云[1] 于雪莲[1] 汪学刚[1] 

机构地区：[1]电子科技大学电子工程学院,四川成都611731

出　　处：《雷达科学与技术》2014年第5期527-531,共5页Radar Science and Technology

摘　　要：在新型的天气雷达中，由于地面杂波反射强度能达到30～55 dB，为了测量雨水强度，要求旁瓣电平小于60 dB。相对于线性调频信号通过幅度加权得到低旁瓣输出，非线性调频信号（NLFM）无需加权就可以得到很低的主副瓣比，因此没有加权引起的信噪比损失和主瓣展宽等问题。但是对非线性调频信号直接匹配滤波只能获得-40 dB左右的主副瓣比，无法满足天气雷达实际应用的需要，因此文中提出一种基于非线性调频信号的改进设计方法，仿真结果表明，该方法可以有效降低旁瓣电平，获得-73 dB的主副瓣比，但也会引入一定的信噪比（SNR）损失。In the modern weather radar,the echo of the ground clutter can reach 30-55 dB.So the nor-malized sidelobe must drop to -60 dB in order to measure the intensity of the rain.In contrast to the linear frequency modulation signal（LFM）,it must use amplitude weighting to lower the sidelobe level,so the per-formance of the nonlinear frequency modulation signal（NLFM）is good.The sidelobe level can achieve very low without window weighting,so there is no the loss of signal-to-noise ratio and the mainlobe width also should not be widened.But the result of the nonlinear frequency modulation signal can only reach -40 dB, which can not meet the requirements in applications.So other methods must be put forward.This paper pro-poses a new method to design NLFM,the simulation results show that this method can reduce the sidelobes effectively and the ratio of the mainlobe to the sidelobes can achieve -73 dB,but there is a loss of SNR.

关 键 词：脉冲压缩 非线性调频信号 相位逗留法 幅度加权函数的设计 

分 类 号：TN958.3[电子电信—信号与信息处理]