Metamaterial-based patch antenna with wideband RCS reduction and gain enhancement using improved loading method

The simultaneous improvement of radiating and scattering performance of an antenna is normally considered as a contradiction. In this study, wideband radar cross-section (RCS) reduction and gain enhancement are both achieved for a conventional patch antenna by loading metamaterial in an improved way. First, two artificial magnetic conductor units are selected to construct a chessboard-like metamaterial surface (CLMS) which has wideband low RCS property. Then the CLMS is applied to a conventional patch antenna for the purpose of RCS reduction. Through a detailed investigation of three loading manners, a metamaterial-based patch antenna with both improved RCS and gain is proposed and experimentally validated. Both simulated and measured results show that, compared with the original antenna, the gain of the proposed antenna is enhanced almost over the whole operation band, and the wideband (in-band and out-of-band) RCS reduction is achieved concurrently.