基于FMCW合成孔径雷达抗欺骗干扰方法研究

Anti-Deception Jamming Method for Frequency Modulated Continuous Wave Synthetic Aperture Radar

研究雷达信号调频优化问题,由于合成孔径雷达干扰的欺骗性和复杂性,调制带宽会影响抗干扰性能。为解决上述问题,提出一种调频连续波体制的随机初相与限幅过程相结合的成像雷达抗干扰方法。通过在发射信号中加入随机变化的初始相位、发射诱骗信号截获干扰脉冲并对其进行方位压缩、限幅,然后在方位向上进行逆傅里叶变换和逆滤波并用真实滤波函数进行匹配滤波,最后按照传统调频连续波合成孔径雷达成像方法进行成像。同时通过提高脉冲重复频率增加方位向脉冲积累个数,使成像信干比得到提高,进而使接收端抗干扰性能得到增强。仿真结果证明,与直接进行真实信号匹配滤波相比,加入限幅过程和提高脉冲重复频率使干信比提高了30dB。

This article studied the problem of radar signal frequency optimization.Considering the deception and complexity of jamming for synthetic aperture radar（SAR）,modulation bandwidth can influence the anti-jamming performance.In order to solve the problem,this article presented the anti-jamming method of random initial phase combined with amplitude limitation for imaging radar based on frequency modulated continuous wave（FMCW） system. In this method,a random initial phase was added into transmitting signals,and the interfering signal was intercepted by transmitting induced signals and used as a matched filtering function for azimuth compression and amplitude limitation.After inverse azimuth Fourier transform and inverse matched filtering were carried our,the real matched filter was used and the normal FMCW SAR imaging method was implemented.At the same time,the accumulated pulse number at azimuth direction and the signal jamming ratio（S/J） of imaging increased by increasing the pulse repetition frequency（PRF）,and the anti-jamming performance at receiver was enhanced.Simulation results testify that compared with matched direct filtering with real signals,the jamming signal ratio（J/S） can increase 30dB using this method.