Inverse Design of Broadband Artificial Magnetic Conductor Metasurface for Radar Cross Section Reduction Using Simulated Annealing

In this study, we present a novel design methodology for unit cells in chessboard metasurfaces with the aim of reducing the radar cross-section (RCS) for linearly polarized waves. The design employs rotational symmetry and incorporates ten continuous parameters to define the metasurface units, enabling the creation of flexible 2D structures. The geometrical parameters of the two units are then optimized using a simulated annealing (SA) algorithm to achieve a low RCS chessboard metasurface. Following optimization, the properties of the metasurface were experimentally verified. The experimental results show a significant RCS reduction of 10 dB within the 7.6–15.5 GHz range, with the peak reduction reaching-28 dB at normal incidence. For a bistatic RCS, the metasurface effectively scatters incident waves into four distinct lobes. The proposed method offers an alternative strategy for the inverse design of low RCS metasurfaces and can be extended to applications in polarization control, phase gradient manipulation, and transmissive metasurfaces.