An ultra-broadband double-layer AMC surface for RCS reduction

A novel artificial magnetic conductor (AMC) surface is designed for radar cross section (RCS) reduction in ultra-wide band. The proposed AMC structure is composed of two different double-layer AMC units, resulting in destructive reflection phase difference (180°±37°) in the band from 5.8 to 16.35 GHz (95.26%). Each AMC unit cell is combined by a metal patch etched on a substrate and a PEC layer, in between of which is a 2-mm-thick air gap. One of the metal patches is composed of an octagonal ring and a Union Jack cross, and the other is a circle patch. With chessboard arrangement by the two units, the RCS of the proposed surface can achieve an 91.7% (6.2-16.7 GHz) 10 dB RCS reduction bandwidth for x polarization and an 93% (6.1-16.7 GHz) bandwidth for y polarization, which demonstrates that the presented AMC surface may be found potential applications on low-RCS platforms in an ultra-wide band.