Ultra-low radar cross-section realized by metasurface with nonuniform elements

Abstract

A novel checkerboard metasurface is proposed to realize broadband ultra-low radar cross-section reduction (RCSR). The metasurface element is a non-uniform array which contains two uniform subarrays composed of 3 × 6 metallic patches. The reflection phases of the two subarrays can be compensated each other. Based on this characteristic, the non-uniform element reflects two orthogonally polarized waves with a phase difference shrinking to 180 ± 20° in a wideband from 11.2 to 23.0 GHz. When the non-uniform elements are arranged into a checkerboard structure, two co-polarized reflective waves with phase difference of 180 ± 20° are then generated for arbitrary polarized incident waves, resulting in an ultra-low RCS reduction. Simulation results show that the proposed checkerboard metasurface achieves at least 15 dB RCS reduction from 11.2 to 23 GHz (69%) for normal incident waves. The experimental results are good agreement with the simulations.