Amplitude-Phase Measurements of Near-Field Scattering of Vortex Electromagnetic Wave by Regular Targets

In this paper, the amplitude-phase distribution measurements of the scattering near field of vortex electromagnetic wave is conducted in a microwave anechoic chamber environment by utilizing a robotic system for automated testing and analysis of antenna near-field characteristics. The reliability of the measurement data is verified by comparison with the simulation results produced by the FEKO software. The effects of beam parameters, the polarization of vortex waves and the position of the receiving field are analyzed based on the measurement results. The results demonstrate that the near-field amplitude of the target irradiated by the vortex beam is contingent upon the irradiated target's shape and the beam's parameters. This work may provide a foundation for the further utilization of the near-field scattering characteristics to obtain more information about the radar target.