A Broadband Low RCS Antenna Based on Polarization Conversion Metasurface

In this paper, a polarization conversion unit consisting of a notched square ring and a cross structure with different lengths is designed. An air layer is added between the dielectric substrate and the grounding plate of the unit to broaden the working bandwidth. The unit can convert the normal incident wave of linear polarization into cross polarization within 7.91-25.01 GHz, and the polarization conversion bandwidth is 103.88%. A low RCS slot array antenna based on polarization conversion metasurface has been designed, the RCS reduction can reach more than 10dB within 8.36-23.38 GHz, which is very effective in reducing RCS.