Sidelobe reduction in Synthetic Aperture Radar (SAR) using Multi Stages of Linear Frequency Modulated (MS-LFM) pulse

A commonly used Synthetic Aperture Radar (SAR) pulse is the Linear Frequency Modulated (LFM) pulse. It has the advantage of greater bandwidth while keeping the pulse duration short and the envelope constant. However, the matched filter output of this signal contains range sidelobes with the first sidelobe at a level of -13.2 dB to the peak of the main lobe. In this paper, the linear frequency modulation (LFM) waveform and matched filter response are introduced. The principle of Multi Stages of Linear Frequency Modulation (MS-LFM) is also discussed. Simulation results of the proposed MS-LFM signal are presented, where sidelobe level reduction of more than -20 dB can be achieved.