Design of Phase-Modulated Metasurfaces for Beam Steering in Fabry–Perot Cavity Antennas

A simple model allowing us to predict beam steering characteristics in a Fabry-Perot (FP) cavity antenna is presented in this letter. The structure consists of a ground plane and a phase-modulated metasurface used as a partially reflective surface (PRS). The aim of this letter is to present a simple model that allows calculating the necessary phase modulation for a desired beam-steering angle. Furthermore, phase-modulated metasurfaces are designed by varying the PRS inductance, and the model is validated both numerically and experimentally on antennas designed to operate around 2.25 GHz.