A Multimode-OAM Imaging with Gaussian Filters for 2D Dielectric Targets with Arbitrary Shapes and its Symmetrical Investigation

This paper presents a 2D multimode-OAM imaging method equipped with Gaussian filters for dielectric targets and its symmetrical investigation. Factors to be analyzed include those for OAM generators, such as radius for varied antenna arrays, steps and ranges of fractional OAM modes, and others for reconstruction algorithms in imaging operations. Several effects are discovered and quantified. The first is that generator selections are critical for inverse imaging depending on shapes and contrast. Simulation results demonstrate that a 0.65 m array radius and a 0.5 mode of step offer optimal performance for uniform circular arrays (UCAs). Another is that symmetrical utilization of both positive and negative OAM modes produces a synergistic enhancement in image reconstruction fidelity and target differentiation accuracy. After Gaussian filtering of the outputs of imaging operations, the method is tested and confirmed stable for arbitrary-shaped dielectric targets, which could provide practical guidance for OAM-based imaging design.