DESIGN AND DEVELOPMENT OF AN ULTRATHIN TRIPLE BAND MICROWAVE ABSORBER USING MINIATURIZED METAMATERIAL STRUCTURE FOR NEAR-UNITY ABSORPTION CHARACTERISTICS

This article discusses about the design and development of an ultrathin triple band microwave absorber using a miniaturized metamaterial structure for near-unity absorption characteristics. In order to design a miniaturized metamaterial (MTM) absorber unit cell with triple band response, two resonators, named as Structure-I and Structure-II, are configured within the single unit cell. The geometrical proportions of the suggested resonators have been chosen in such a manner so that Structure-I can contribute one absorption band while Structure-II can contribute two absorption bands. Therefore, the combination of two resonators offers triple band response with the highest absorption values of 99.04%, 99.62%, and 99.33% at the frequencies of 4.25 GHz, 8.35 GHz, and 11.06 GHz, respectively. Additionally, the suggested absorber unit cell claims miniaturization with total electrical size of 0.156λ0 × 0.156λ0 × 0.014λ0, where λ0 corresponds to the free-space wavelength at the first peak absorption frequency of 4.25 GHz. Additionally, the electric field and vectored surface current distribution along with the input impedance graph has been used to discuss the absorption methodology of the suggested structure. Further, the MTM belongings of the suggested structure have been illustrated with the dispersion curve.