A Low-Profile Broadband Frequency Reconfigurable Patch Antenna Based on Metasurface

In this paper, a low-profile broadband frequency reconfigurable patch antenna based on a metasurface is proposed. The antenna consists of an upper metasurface layer consisting of square patches and a lower patch antenna layer. Varactors are inserted between the square patches of the metasurface layer, and the capacitance value of the varactors is controlled by a single DC voltage source to change the operating frequency of the antenna to achieve the function of frequency reconfiguration. Simulation results validate the performance of this antenna. The antenna can achieve continuous frequency tuning within 4.22-5.17 GHz with a single operating state bandwidth of up to 10% (4.68-5.17 GHz). The gain of the antenna can be maintained in a stable state from 6.3-7.4 dBi in all operating bands.