Electromagnetic (EM) vortex waves carrying orbital angular momentum (OAM) have a helical wavefront structure, which allows the echo signal to contain the azimuthal information of the target when performing radar detection tasks, thus they show great potential in the field of staring imaging. It has been demonstrated that EM vortex radar (EMVR) based on the uniform concentric circular arrays (UCCAs) achieves equal divergence angles, so that the target can be simultaneously illuminated by multimode OAM beams. However, the imaging performance of EMVR is affected by the Bessel function term, which makes it difficult to achieve focused imaging results under limited OAM modes and apertures. To address this issue, a fast and high-resolution method based on accelerated 2-D alternating direction method of multipliers (2-D-ADMM) is proposed. First, an imaging model based on beam steering is established to effectively improve the detection performance, and the elevation resolution and azimuth resolution for EMVR are der

Alternating direction method of multipliers (ADMM), electromagnetic vortex radar (EMVR), nonuniform fast Fourier transform (NUFFT), orbital angular momentum (OAM), uniform concentric circular arrays (UCCAs)