A New Method of Phase-Perturbed LFM Chirp Signals for SAR ECCM

The active coherent jamming based on Digital Radio Frequency Memory (DRFM) is an effective method of jamming for synthetic aperture radar (SAR). The traditional linear frequency modulated signal (LFM) signal synthetic aperture radar has poor capability of counting active coherent jamming. In this paper, a new SAR signal based on phase-perturbed LFM (PPLFM) signal was proposed to improve the ability of radar to resist active coherent jamming. First, the design method of PPLFM signal is presented, after which the disturbance amplitude matrix is optimized. Then the electronic counter countermeasures (ECCM) performance and imaging performance of the PPLFM signal are analyzed with different disturbance parameters. Finally, the ability to suppress false target jamming and frequency shift jamming is compared with the LFM signal. Simulation results show that the PPLFM signal can effectively suppress the active coherent jamming compared with the LFM signal.