Wideband radar cross section reduction using a novel design of artificial magnetic conductor structure with a triple-layer chessboard configuration

Abstract

A novel wideband three-layer chessboard-like structure is proposed to reduce the radar cross section (RCS) of the radar target. This configuration is composed of two artificial magnetic conductor (AMC) cells formed by two crossed ellipses with different sizes in two cells. A desired 180° ± 37° phase difference is achieved by combining these unit cells and the measured 10 dB RCS-reduction bandwidth is extensively broadened to more than 96% (from 8.11 to 23.32 GHz, covering X, Ku, and K bands for different radars) in comparison with the other works. This characteristic is obtained by carefully adjusting the positions of all resonances using the proper sizes for the ellipses and the proper dielectric constants and thicknesses for the three layers. Although, the proposed design has three layers with the overall thickness of 2 mm, it is still thinner than most of the recent related works. This low-profile structure is also cost-effective due to the fact that 60% of the overall thickness is formed by an air substrate. The proposed cells are designed, simulated, and fabricated in a chessboard-like configuration for both monostatic and bistatic RCSs. Simulations and measurements are in a good agreement, which shows the capabilities of the design.