Triple Band Polarization Insensitive Ultrathin Metamaterial Absorber

This paper proposes a triple band electromagnetic absorber for C and X band applications. The absorber is made on FR4 substrate using an encircled diamond structure with cross splits in them. The proposed absorber shows a stable absorption response for the various angle of incidence and polarization. The absorption bands of the absorber are at 4.05 GHz, 6.09 GHz, and 8.10 GHz. The amount of absorptivity in these 3 bands are 93.57%, 96.51%, and 93.88% respectively. The metamaterial behavior of the absorber is evident from the perfect impedance matching obtained at these 3 frequency bands. The absorber is ultra-thin with the thickness of lambda(0)/47 at the lowest frequency of absorption. The performance of the absorber is tested using the single antenna method in free space and the results are in good agreement with the simulation.