Broadband Multiple Vortex Beam Generation Based on Pancharatnam-Berry Phase Metasurface

In this paper, a metasurface for generating broadband deflection vortex beams based on the Pancharatnam-Berry (PB) phase principle is proposed. The units with different phase responses are arranged according to the calculated vortex phase compensation matrix, thereby the proposed metasurface can convert the incident plane wave into a reflected high-purity third-order vortex wave within a broadband from 14 GHz to 20 GHz, and the relative bandwidth is 35.3%. In addition, by adding beam deflection phase distribution to the vortex phase distribution, reflected vortex wave towards specified direction can be obtained. Therefore, it is possible to achieve modulation of multiple modes, multiple beams, and capability of customizing beam of vortex waves by compositely designed metasurface. The approach can be used to design metasurfaces generating desired vortex waves in complex communication scenarios, thereby can further expand the application of vortex waves in wireless communication.