An ultra-thin compact wideband metamaterial absorber

Abstract

This article reports an ultra-thin, compact metamaterial absorber with wideband absorption at microwave frequencies. The proposed structure contains circular and rectangular split rings, and has thickness of 0.049λ0 with respect to the center frequency of the bandwidth. This structure provides wideband absorption of 3.84 GHz from 12.80 GHz to 16.64 GHz with 90% absorptivity and absorption peaks are observed at 13.2 GHz and 16.5 GHz. The full width half maximum of the structure is 5.48 GHz from 12.09 GHz to 17 57 GHz. The absorption mechanism and polarization behavior of the structure have to be studied. The proposed metamaterial absorber is sensitive to polarization but wideband absorption is attained only for specific normal and oblique angles of incidence, with reduced absorptivity. The structure has been fabricated, and the measured results match well with the simulation responses. The advantage of the proposed absorber is its wideband absorption with compact (8 mm × 8 mm size), ultra-thin (1 mm thick substrate) structure compared to that of the other existing microwave metamaterial absorbers.