A Compact Ultrathin Ultra-wideband Metamaterial Microwave Absorber

Abstract A simple design of compact ultra-wideband, ultra-thin metamaterial microwave absorber has been presented. The unit cell of the proposed design is composed of diagonally placed ‘microstrip bend’ like patches printed on grounded dielectric substrate. The simulation results demonstrate the 10-dB absorption bandwidth of 7.19 GHz from 10.45 GHz to 17.64 GHz and FWHM (full width at half maximum) bandwidth of 11.43 GHz from 9.61 GHz to 21.04 GHz. The proposed design presents more than 90% absorption for a bandwidth of 1.02 GHz at wide angle of incidence up to 60°. The absorption mechanism has been analyzed through surface current and electromagnetic field distributions. The proposed design has been fabricated and experimentally tested for its 10-dB absorption bandwidth under different polarization and oblique angles of incidence of electromagnetic wave. The designed absorber is low profile (unit cell size is ~0.257 λ0 at the center frequency corresponding to 10-dB absorption bandwidth), ultrathin (~λ0/14 thick at the center frequency) and provides a novel design of wideband absorber for many useful applications.