Design of Wideband Vortex Reflectarray Based on Pancharatnam-Berry Metasurface

In this paper, a design of a wideband vortex reflec-tarray based on Pancharatnam-Berry (PB) metasurface is proposed, which consists of 20×20 elements. The patch is composed of an I-ring inlaid with an opening ring and is printed on the surface of the substrate. The other side of the substrate consist of a foam layer and a metal ground. A 360° reflection phase is achieved under the circularly polarized (CP) incidence. The simulation results show that the vortex beam carrying $l=+2$ orbital angular momentum (OAM) mode is successfully generated from 20-40 GHz, with an OAM bandwidth of 66.6%.