Flexible Secondary Beamforming Using Holographic Meta-Surfaces for Multi-Mode Vortex Beam Transmission in Wireless Communications

This paper introduces an innovative approach to realizing adaptable secondary beamforming using a dual holo-graphic reflective meta-surface, which comprises a transmitting reflective meta-surface A and a transforming meta-surface B, both designed in accordance with holographic theory. Meta-surface A is specifically engineered to generate multi-mode vortex beams, serving as the initial stage of beamforming. Meanwhile, holographic meta-surface B is employed to convert the multi-mode vortex beams into two spherical waves with distinc-t directions. The holographic meta-surface system undergoes simulation, fabrication, and measurement at 10 GHz. Results demonstrate the efficacy of the proposed method in achieving robust and flexible beamforming. This system, characterized by its low profile, simplicity, and cost-effectiveness, holds significant promise for the transmission of multi-mode vortex beams in wireless communication scenarios.