ON THE INFLUENCE OF COUPLING AMC RESONANCES FOR RCS REDUCTION IN THE SHF BAND

A novel approach to Radar Cross-Section reduction using a thin Artiflcial Magnetic Conductor (AMC) structure is presented. The novel AMC structure combines two unit-cell metallization sizes and so it presents two resonant frequencies. RCS reduction is based on destructive interference of two partial re∞ections. Taking as starting point a previous work showing signiflcant RCS reduction based on the combination of two AMC surfaces with overlapped AMC operation bandwidths (so that they have similar re∞ection coe-cient amplitude) without a 180 - -phaseshift, the key point of this contribution is to analyze the in∞uence of the degree of the aforementioned overlapping on RCS reduction and to show that this achievement is based on coupling phenomena. A comparison of the achieved RCS reduction when combining two AMCs whose AMC operation bandwidth overlaps, two AMCs with non-overlapped AMC operation bandwidths, and PEC-AMC is presented. Prototypes of these three combinations have been manufactured (having them the same size) and their RCS has been measured in an anechoic chamber.