An ultra-thin polarization-independent wide-angle metamaterial absorber for dual-band applications

This paper proposes an ultra-thin polarization-independent metamaterial absorber for dual band applications. The single unit cell consists of two cave ring resonators backed by metallic plane separated by a dielectric layer. The dimensions of the structure have been optimized so that absorptions take place at two distinct frequencies 5.8 and 8.83 GHz (with absorptivities 99.1% and 99.5% respectively) operating at the FCC radar frequency spectrum. The proposed structure is more compact, consuming lesser area compared to the conventional rectangular closed-ring resonators. It is polarization-insensitive and also shows high absorption (above 80%) upto 60° for both TE and TM incidence.