A novel, mutual coupling independent, ultra-thin, and polarization-insensitive tetra band metamaterial absorber for microwave applications

This manuscript presents a novel, highly efficient, wide-angle, and polarization-stable symmetrical single-layered metamaterial absorber (MA) on a 0.8 mm thin dielectric layer that exhibits four distinct absorption peaks having 0.019λ∘, 0.027λ∘, 0.038λ∘, and 0.044λ∘, respectively. The amalgamation of two circular rings surrounded by a square-shaped four split ring resonators (RR) including a combined group of a circular patch and a square ring in a unit cell enabled mutually coupling independent environment amongst the inter-elements and resulted in a compact geometry. The inclusion of the relevant sub-elements in the proposed MA demonstrated polarization-insensitive characteristics over wide angles of incident waves for both transverse electric (TE) and transverse magnetic (TM) at four frequency bands, i.e. 7.16 GHz, 10.175 GHz, 12.92 GHz, and 16.82 GHz having 99.6%, 97.2%, 98.3%, and 94.8% absorptivity, respectively. The experimental validation of the prototype to validate the simulated results is performed in an anechoic chamber.