High-accuracy beam generation and scanning using reconfigurable coding metasurface

Abstract

Abstract Metasurface technology has attracted widespread attention, owing to its remarkable capability to control electromagnetic properties. In this paper, we design a reconfigurable reflective metasurface array operating at 5 GHz for beam generation and scanning based on coding metasurface. Field programmable gate array (FPGA) is equipped for switching the states of PIN (positive-intrinsic-negative) diodes loaded on the metasurface in real-time, resulting in a 180° phase difference. To obtain multi-beam radiation and high-accuracy beam steering, the coding sequence to produce the target radiation pattern is calculated by an algorithm program. We design the fitness function of a genetic algorithm (GA) to optimize the sequence corresponding to the target directions. The simulation result shows that with the accuracy of 1°, the proposed metasurface is capable of generating multi-beam and scanning two-dimensional beams within the 50° range. Further, we fabricate and measure a prototype sample of 15 × 15 elements, which is verified feasible by comparing the measured result and the simulation. This work demonstrates the great potential of applying this reflective metasurface to wireless communication or radar.