Range Grating Lobes Suppression Techniques for SAR Mode Based on Intra-Pulse Frequency Agility Waveform

Designing waveforms with intra-pulse frequencyagile signals offers a way to actively counter jamming like interrupted sampling repeater jamming (ISRJ) and noise jamming in SAR systems. However, these signals naturally produce strong grating lobes in the range direction after pulse compression, which harms image quality. To fix this, we present a method using amplitude and phase correction. By leveraging differences in the frequency spectra between stepped-frequency signals and intra-pulse agile signals, we designed a frequencydomain filter to effectively suppress these range grating lobes. First, we analyzed why these grating lobes happen using the signal's ambiguity function. Then, our correction method, combined with the filter, rebuilds and optimizes the range spectrum of the echo signal. This successfully reduces the grating lobes. Finally, we tested our approach through simulations and confirmed it works.