Copolarized and Cross-Polarized RCS Imitation Based on Amplitude and Phase Controlled Metasurface

This letter presents a method for copolarized and cross-polarized radar cross section (RCS) imitation based on an amplitude and phase controlled metasurface. By establishing the quantitative relationship between the polarization scattering matrix and the metasurface's reflection coefficients, anL-shaped patch element is designed to achieve quasi-continuous amplitude control and 1-bit phase switching for both polarization channels, by rotating the element within 0°-45° and 90°-135° ranges. A genetic algorithm is employed to optimize the amplitude and phase distributions of the metasurface to imitate the co- and cross-polarized RCS of targets. Experimental results of three 16 × 16-element prototypes demonstrate that imitation errors remain around 1.5 dB within the experimentally validated range of 9.5 GHz to 10.5 GHz and elevation angles within 16°. The results validate the effectiveness of the proposed approach for polarimetric RCS imitation in the joint frequency-angle domain..