Design of a Metasurface with Wide RCS Reduction Bandwidth

This paper discusses the design of a metasurface with low radar cross-section (RCS) property. Three different configurations of metasurface including chessboard-like configuration, triangular-shaped configuration, and optimized configuration, with the help of artificial magnetic conductor (AMC) unit cells, are designed to construct the low scattering surface. Two different AMC unit cells with 180° ± 37° phase difference are designed to obtain the out of phase reflection in a wide frequency band. Then, these AMC unit cells are employed into different configurations to study the RCS reduction bandwidth. The simulated results show that the chessboard-like metasurface and triangular-shaped metasurface redirect the incident electromagnetic energy into four and eight scattering lobes away from the normal direction. Due to the more scattering lobes, the triangular-shaped metasurface exhibits a wide 10dB RCS reduction bandwidth. To further widen the RCS reduction bandwidth, the placements of the AMC unit cell are further optimized using a genetic algorithm to construct the optimized metasurface. The designed optimized metasurface diffuses the scattering lobes with less scattering amplitude in the normal direction. This investigation explains that the optimized metasurface shows a wide 10 dB RCS reduction bandwidth as compared to the chessboard-like configuration and triangular-shaped configuration. To further validate the RCS reduction performance of the metasurfaces, the bistatic RCS analysis of the chessboard-like surface, triangular-shaped surface, and optimized metasurface is presented and compared with the metallic plate. The analysis shows that the designed metasurface show an obvious RCS reduction as compared to the reference metallic plate in the monostatic and bistatic configuration. Therefore, the designed metasurfaces can be utilized in the stealth platforms where low observability of the surfaces is required.