Polarization‐Insensitive Multivariate Hybrid Metasurfaces for Wideband RCS Reduction

ABSTRACT In this article, polarization‐insensitive hybrid metasurfaces are presented for broadband radar cross section (RCS) reduction using a multi‐parameter optimization technique. The unit cell consists of a 45°‐rotated square‐loop metallic patch printed on a dielectric substrate backed by a ground plane. Three geometrical variants of the unit cell are designed by varying the pattern dimensions and substrate height, such that the reflection phase differences among the elements produce wideband destructive interference leading to RCS reduction. Two metasurface arrangements are investigated: one using a checkerboard configuration and the other using a Genetic algorithm (GA)‐optimized layout, which result in 10 dB RCS reduction bandwidths of 5.5–11.8 GHz (72.83% fractional bandwidth) and 5.8–13.2 GHz (77.89%), respectively. The novelty of the proposed work lies in the comprehensive numerical analysis and hybrid fabrication technique that integrates FR4 and 3‐D printed PLA substrates with tailored heights, enabling multivariate phase control for wideband low‐RCS response. Both metasurfaces exhibit polarization‐insensitive performance and maintain stable RCS reduction up to 30° oblique incidence. The fabricated geometries are validated through experimental measurements, showing strong agreement with full‐wave simulations.