Broadband Metamaterial Surface for Antenna RCS Reduction and Gain Enhancement

This paper presents a broadband metamaterial surface with low radar cross section (RCS) and introduces its application on antenna. The metamaterial surface is composed of polarization-dependent artificial magnetic conductors (PDAMCs), which are orthogonal arranged in chessboard-like configuration for backscatter cancellation. By optimizing the PDAMC cell, effective phase difference is obtained in wideband and the surface achieves 10dB RCS reduction over the bandwidth of 32%. As a potential application, the metamaterial surface is employed to replace the metallic ground of a slot antenna. Illustrated by detecting wave, the novel antenna shows low RCS at boresight. While the antenna operates, the gain gets enhanced as a result of parasitic radiation of the surface. Full wave simulations and measurements validate that the novel antenna achieves both broadband low RCS and high gain compared with the slot antenna installed on a same-size metallic plate.