Research on SAR Imaging Method Based on Vortex Electromagnetic

Radar imaging was widely used in various fields due to its advantages of all day and all weather. Vortex electromagnetic (EM) waves had higher degrees of freedom than plane EM waves. Synthetic aperture radar (SAR) imaging combined with vortex EM waves provided the possibility for high-resolution radar imaging. In this paper, a vortex EM wave SAR imaging method was proposed, and the vortex EM wave in orbital angular momentum (OAM) mode changes linearly with slow time. The compression imaging was performed in the two-dimensional frequency domain after compensation of the introduced Bessel term and azimuth angle first-order term. Through numerical simulation and comparison experiments, it was verified that the algorithm in this paper has higher azimuth resolution and better imaging performance, and the azimuth resolution was gradually improved with the increase of OAM mode.