On the effect of array size on the radar cross section reduction bandwidth of checkerboard metasurfaces

Abstract This paper reports investigations on the effect of array size on the RCS reduction bandwidth of checkerboard metasurfaces (CMS). Three CMSs, one on a Rogers substrate and the remaining on FR4, are considered. While the usual phase deviation criteria are used for the designs on both the substrates, additionally a set of modified criteria recently proposed are used for the FR4 substrate-based designs. While three different sizes – 120 mm2, 240 mm2, and 480 mm2 – are considered for the simulation-based investigations for all the structures, an additional size of 600 mm2 is also considered for one of them. The 8 and 10 dB RCS reduction bandwidths drop as array size increases. The bandwidth reduction is attributable to mutual coupling, as has been reported in an earlier study. As therefore expected, all of the three structures, for all sizes, present the same RCS reduction bandwidth when a mutual coupling mitigation technique is incorporated. For 10 dB RCS reduction bandwidth, this value approaches that estimated by using a mutual coupling independent semi-empirical equation that holds for infinite arrays.