Abstract
A polarization-insensitive multi-band metamaterial absorber comprised of four concentric rectangular rib structures, mounted over a dielectric medium, was investigated. The performance of the absorber was studied under different polarization and oblique incidence angles. Both the transverse electric (TE) and transverse magnetic (TM) incidence radiations were exploited to investigate the absorption characteristics. It was found that the four-fold symmetry in the configuration makes the absorber to remain insensitive under the influence of such operational conditions. The proposed structure yields four independent high absorption peaks within the 5G spectral range. The absorptivity of the structure was also investigated for various values of the thickness of dielectric substrate on which the metasurface was constructed. The electric field and surface current distribution patterns were also obtained corresponding to three different resonance peaks. It is expected that this kind of absorber would be effectively used for 5G applications in the context of MIMO antennas.