SAR imaging based on OAM-ωK algorithm

Traditional radar imaging was restricted by the antenna aperture and imaging scene. It was difficult to improve azimuth resolution greatly. The vortex electromagnetic (EM) waves carrying orbital angular momentum have a special helical phase wavefront structure. The vortex EM waves could bring more degrees of freedom when applied to synthetic aperture radar imaging, make it possible for ultra-high resolution imaging, provide a new possibility for the bottleneck problem of azimuth resolution in traditional radar imaging. In this paper, an OAM-ωK algorithm was used to compensate the Bessel term and residual azimuth angle term which in the echo signal. Because the azimuth term and azimuth angle term were fused into a new azimuth term, the Doppler bandwidth was broadened and high resolution imaging was achieved. The theory verified the advantages of the algorithm in azimuth resolution. By comparing simulation experiments of single target point and multi-target points with the traditional aK algorithm, the proposed OAM-ωK algorithm had higher azimuth resolution, proving the algorithm's effectiveness.