Multi-band Metasurface Microwave Absorber Based on Square Split-Ring Resonator Structure

Abstract

A multi-band microwave metasurface (MS) absorber based on the square split-ring resonators (SSRR) is designed and analyzed. The proposed MS structure comprising of two metallic layers followed by two FR4 materials, and an air gap to separate the dielectric layers. In the bottom layer, a full copper layer is placed to prevent back-wave transient. The performance of the proposed MS absorber is investigated using CST Microwave Studio, and the simulated results show that it can achieve absorption peaks at 1 GHz, 2.4 GHz, 5.7 GHz, and 6.7 GHz with the absorption of 98%, 99.6%, 99.7%, and 99%, respectively, under normal incidence. In oblique incidence, the absorption response values of more than 95% are observed for all the operating frequencies at different incident angles. In addition, the E-field and current distributions are analyzed to illustrate the proposed MS absorber’s physical absorption mechanism.