High-gain and Low-RCS Linear Polarization F-P Resonant Cavity Antenna Based on Metasurface

Fabry-Perot (F-P) resonant cavity antenna is a high-gain antenna, which can increase the gain of microstrip antenna significantly, without a complicated feed network. It has a simple structure and it is easy to process. In this paper, the polarization grid structure and the zigzag structure are combined to design a linear-circular polarization conversion metasurface unit. This unit can convert the linearly polarized incident wave that is perpendicular to the polarization grid into circularly polarized transmitted wave in the range of 9.26~10.84 GHz. The unit and its mirror image unit are arranged in a checkerboard shape as a metasurface and placed above the microstrip antenna. Thus a linear polarized F-P resonant cavity antenna with high gain and low radar cross section (RCS) is proposed. In order to verify the performance of the antenna, the F-P resonant cavity antenna was processed and measured. The measured results and simulated results have shown good consistency. Compared with the original microstrip antenna, the polarization purity of the F-P resonator cavity antenna is enhanced in the range of 9.55~9.85 GHz, and the gain is improved in the working frequency range of 9.50~10.04 GHz with a maximum increase of 5.55 dB, and the RCS reduction was achieved in the range of 9.47~11.97 GHz with a maximum reduction of 17.47 dB.