An Effective Coherent Noise Jamming Method for Deception of Wideband LFM Radars

Linear frequency modulation (LFM) waveform is widely used in modern tracking radars for high resolution. Self-protection jamming systems are designed to deceive the targeted radar by generating false targets in range. The proposed jamming technique the jamming signal is acquired by dividing the intercepted radar signal into several equal chunks by bandwidth division, and then finds optimal retransmission order. After dividing the radar signal into multiple chunks, we impose phase modulation on intercepted radar signal. The resultant jamming signal is coherent with the matched filter, and provides considerable processing gain to the jamming signal which generates false target peaks. The jamming signal enhances the detection threshold as the real target is surrounded by false target in non-symmetrical order. The characteristics of bandwidth division and phase modulation are analyzed in detail and then the jamming signal model is presented. Simulation results are presented to validate the correctness and effectiveness of the jamming method. Comparing with the conventional coherent noise jamming, the proposed jamming signal model is capable of generating a greater number of false targets after CFAR detection. The jamming effect to the hostile radar is analyzed at the plan position indicator (PPI) of radar which generates track of multiple false targets after passing through radar signal processing module.