Bandwidth enhancement of Salisbury screen microwave absorber using wire metamaterial

A new design approach that enhances the bandwidth of conventional Salisbury Screen (SS) microwave absorber is investigated. The absorber comprises of, wire metamaterial printed on FR4 substrate, placed on the top of the SS. The SS consists of 50 Ω/sq resistive sheet placed on the metal backed dielectric spacer. The theoretical analysis indicates the bandwidth of SS for −10 dB reflection is 41.1% using FR4 as a spacer for the optimum sheet resistivity of 308 Ω/sq. The proposed absorber shows the bandwidth of 53.5% (8.9–15.4 GHz) for −10 dB reflection. The thickness of the absorber is 0.15 λL (lowest cut-off frequency for −10 dB reflection). The FR4 substrate with SS works as Jaumann configuration and introduces an additional resonance mode. The selective overlapping of resonant mode excited by wire metamaterial and the additional resonance mode enhances the bandwidth of the absorber. The wire metamaterial is physically realized using low-cost screen printing technique. The good agreement between the simulated and measured data has been observed.