Dual-Band Compact Metamaterial-Inspired Absorber with Wide Incidence Angle and Polarization Insensitivity for GSM and ISM Band Applications

Abstract

A dual-band metamaterial inspired microwave absorber composed of concentric two crossed double-arrow shaped resonators, ring resonator with four splits at the corners and square ring resonator is presented. The proposed RF absorber has the absorption feature of wide incidence angle. The sub-wavelength unit cell of the proposed absorber is structured on a metal backed epoxy glass (FR-4) substrate. The novel absorber has two distinct absorption peaks of 99.4% and 98.6% at the frequencies of 1.94 GHz and 2.4 GHz, respectively. The designed structure is polarisation-insensitive with wide incidence angle of 60° and high absorption rate of 82% for transverse electric and 98% for transverse magnetic modes. Polarization insensitivity of the proposed design is investigated by the waveguide measurement technique with setting different orientation angles for the unit cells. The measured and simulated results have good agreement making the proposed absorber a potential candidate for energy harvesting applications in GSM and ISM band.