Wideband Ultra-Thin Polarization Insensitive Flower shaped Absorber

Abstract

A compact ultrathin wideband, wide incidence angle, nearly perfect metamaterial absorber has been proposed in this paper. The unit cell consists of a simple flower shaped resonator with a circular patch and four chip resistors. Under normal incidence, it has absorptivity greater than 90% from 5.55 GHz to 15.39 GHz. While, when the incidence angle is oblique it can achieve absorptivity greater than 80% up to 45° for both TE and TM mode waves. The unit cell electrical area and thickness are $0.22 \lambda_{L} \times 0.22 \lambda_{L}$ and $0.11 \lambda_{L}$ where, $\lambda_{L}$ is the lowest absorption frequency wavelength. Input impedance and field distribution have been discussed to analyze the absorption mechanism.