High-Gain Substrate Integrated Cavity Circularly-Polarized Antenna Loaded with Metasurface

A novel metasurface-loaded high-gain substrate integrated cavity (SIC) circularly-polarized antenna is proposed in this paper. The SIC antenna is fed using Substrate Integrated Waveguide (SIW), and the integration of a hexagonal patch with the feed gap enables the TM121 mode and TM211 mode in the SIC antenna to have equal amplitude and a 90-degree phase difference, achieving circularly polarized radiation. Based on this, a periodic metasurface is designed and loaded on top of the antenna. This metasurface not only broadens the working bandwidth but also further enhances the antenna gain. The antenna gain increased by approximately 2dB without affecting efficiency.