Ultra-thin dual-band perfect metamaterials absorber for microwave applications

Abstract

Abstract This article studies an ultra-thin dual-band perfect electromagnetic metamaterials absorber. It presents a typical artificial microwave structure that can realize multi-band perfect metamaterial absorption. The structure design was implemented by using a Four Quarters of Circle Resonator (FQCR), an ultra-thin FR-4 dielectric substrate and an entire metal plate. The simulated results show two perfect absorption peaks with absorption rates, where the first peak hits 99.35%, and the second peak hits 97.81%. In addition, the ratios of the structure thickness to the wavelengths of the proposed design are 1/82 and are 1/66 at resonance frequency 9.12 GHz and 11.34 GHz respectively, which are ultra-thin comparing with wavelengths. By using the distributions of electric surface current, the mechanism of the ultra-thin dual band is described. This absorber is non-sensitive to the TE polarization wave ranging from 0° to 90° and non-sensitive to the TM polarization wave ranging from 0° to 60° for the first peak and to 45° for the second peak. Furthermore, such multi-band absorber promises many x-band applications, such as harvesting, radar cross section RCS, sensing, antenna enhancement, thermal image and detection.