Grating lobes suppression technique in stepped chirp radar

This paper investigated grating lobes suppression technique in stepped-chirp radar. By means of theoretical derivation, it is concluded that amplitude fluctuation in sub-band signal´s frequency response is a key factor to influence the performance of synthetic bandwidth. It was proved that amplitude modulation in sub-band signal introduces significant grating lobes in pulse compression result. The correlation between grating lobe level and amplitude fluctuation was discussed by theoretical derivation and a novel constraint in stepped-chirp radar system design was proposed. Based on the research above, a grating lobes suppression technique based on compression filter was presented. Amplitude fluctuation in sub-band was compensated by the filter and grating lobes was suppressed. Simulation and experiment data results verified the proposed method.