A novel omega shaped microwave absorber with wideband negative refractive index for C-band applications

This paper reports a polarization controllable and angle-insensitive perfect metamaterial absorber (PMA). The proposed PMA consists of periodically arranged asymmetric omega-shaped resonators made of metallic copper. The absorptivity was analyzed considering the microwave C-band from 4 GHz to 8 GHz. The proposed PMA shows an absorption peak with almost 100% absorptivity at 6.2 GHz. Also, wideband negative index of refraction is observed. Further, the absorber is inspected for the different rotation angles of the top metasurface (omega-shaped ring) along the optical axis, and obliquity of incidence angle for both TE and TM polarized waves. Moreover, surface electric field and surface current distribution were analyzed to understand the absorption mechanism. It was noticed that at resonance (considering 6.2 GHz) electric field maximally remains concentrated on the omega-shaped rings. Furthermore, the simulation and measured results show a good agreement. It is inferred that the proposed PMA would be useful candidate for the sensing and filtering applications in the C-band of the microwave regime.