Monostatic RCS Reduction of Patch Antenna Using 1-bit Checkerboard Metasurface

Through the combination of a single dielectric layer 1-bit encoded unit cell with a patch antenna, we propose a new method for the reduction of monostatic RCS. Our study focuses on a unit cell with a period of $\mathrm{P}=0.2 \lambda$ at 10 GHz, which achieves a polarization conversion ratio (PCR) of 95% from 8.1 to 13.7 GHz. The 1-bit coding sequence comprises the unit cell and its mirrored image, representing “0” and “1”. In order to achieve the required phase difference, a checkerboard metasurface is used by applying the unit cell and its mirrored element. The anisotropic cells surround the patch antenna, which is located in the center of the checkerboard. The metasurface has dimensions of $72 \mathrm{~mm} \times 72$ mm and consists of 128 unit cells. The results indicate that our proposed design, when compared to a patch antenna without metasurface unit cells, reduces RCS by over 7 dB within the frequency range of 8.1 to 13.7 GHz. This results in a reduction of fractional bandwidth by 51.38%.