Design Strategy for RCS Reduction of Metasurfaces Considering Inter-Coupling

Based on the principle of multiphase cancellation, a checkerboard metasurface was designed to reduce the radar cross section (RCS). Each meta-atom in the metasurface features a sandwich structure comprising ring-shaped metal patches of varying sizes, dielectric substrates (FR4) of different thicknesses, and metal ground planes, arranged from top to bottom. Initially, the GA was employed to optimize the meta-atoms, ensuring that their phase response across the frequency band covers the broadest possible angular range. Subsequently, based on the combination of PSO and GA (GA-PSO), optimize the scattering fields of the metasurface across various frequencies, polarizations, and incident angles, aiming to achieve significant RCS reduction. The proposed metasurface demonstrated a 10 dB RCS reduction within the frequency range of 4–40 GHz for normal incident angle. Finally, samples were fabricated and measured, with experimental results showing good agreement with simulation predictions.