A novel jamming method against LFM radar using pseudo-random code phase modulation

Linear frequency modulation (LFM) waveform is widely used in modern tracking radars and missile seekers for high resolution. In this paper, a blanket jamming method for countering LFM radar is proposed based on pseudo-random code phase modulation. Utilizing the structure of digital radio frequency memory (DRFM), we impose phase modulation onto the intercepted radar signal and retransmit it to the victim radar. The characteristics of pseudo-random code are analyzed in detail and then the jamming signal model is presented. Theoretical analyses and simulation results show that by flexible adjusting the parameters of pseudo-random code, different blanket jamming effects can be obtained. Comparing with the conventional noise jamming, the method is capable of obtaining considerable processing gain and taking full use of the jamming power. The proposed method provides an idea for the coherent jamming signal design.