Design of Dual-Band Resistor-Loaded Metamaterial Absorber for ISM Bands Applications

A dual-band, resistor-loaded metamaterial electromagnetic absorber that is polarization-independent and aimed for ISM band applications is presented in the current paper. The suggested metamaterial absorber's unit cell structure is composed of up of three dielectric layers, with an air layer positioned between two cost-effective FR-4 dielectric layers. On the top dielectric layer, two copper square rings are connected using four lumped resistors. The simulation findings show that at the lower (2.45 GHz) and higher (5.8 GHz) frequency bands, respectively, the proposed absorber achieved absorption rates of 99.43% and 99.22%. A sample of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4\times 4$</tex> unit-cells absorber was fabricated and there is a robust link between simulation as well as measurement data. Moreover, the suggested dual-band absorber maintains effective performance across various polarization angles.