OAM-generating method based on concentric-ring array using planar antenna

For OAM-based communications and target detection purposes, the OAM-generating method based on planar antenna and the concentric-ring array is proposed, which can collimate the main-lobe direction and suppress the side lobes simultaneously. The total radiation pattern is derived firstly and the feeding coefficient for each ring is optimized utilizing the genetic algorithm (GA). Subsequently, the planar horn antenna is designed to establish the concentric-ring array in the full wave simulation. Comprehensive simulation results demonstrate that the proposed OAM-generating method can ensure the main lobes of different OAM modes direct in the same angle and the side lobes decrease considerably. The work and results can benefit the OAM's realistic applications for wireless communications and target imaging.