A Multi-band Polarization Insensitive Metasurface Based Microwave Absorber Using Square and Circular Loop with Lumped Elements

A single layer multi-band polarization-insensitive and thin metasurface absorber is proposed. The absorber structure consists of a circular loop and square with two lumped elements connected in the gaps of the middle arm on top of the FR-4 substrate, backed by the continuous metal layer. The absorber has absorption peaks of greater than 95% absorption in the S, Ku, and Ka bands at 3.7, 13.48, and 17.56 GHz with the absorption of 98.4%, 96.6%, and 99.8%, respectively. Findings indicate that the multi-band absorbers have the advantage because the same design can be used for numerous applications for example in stealth technology, sensors, communication systems, thermal detection, and energy harvesting. Moreover, they are used for EM shielding of sensitive electronics at several interference bands.