BANDWIDTH-ENHANCEMENT OF AN ULTRATHIN POLARIZATION INSENSITIVE METAMATERIAL ABSORBER

An ultrathin polarization insensitive microwave metamaterial absorber is discussed, which consists of a periodic array of swastika-like structure printed on FR4 dielectric substrate backed by copper ground. The structure is simulated to give rise to nearly unity (99.64%) absorption at 10.10 GHz (X-band). The proposed structure is symmetric in nature and provides high absorption for any angle of polarization under normal incidence. It also shows high absorption (approximate to 81%) for incident angle upto 60(o). Further, a 2 x 2 array using two different variants of the same resonating structure has been studied and by optimizing its geometrical dimensions, the absorption peaks are brought closer to provide an enhanced bandwidth having full width at half maximum of 0.68 GHz (10.04-10.72 GHz). Both the single-band and bandwidth-enhanced structures are then fabricated and experimentally studied which shows good agreement with the simulated results. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:350-355, 2014