Broadband and Ultrathin Frequency-Dispersive Metamaterial Screen for Reflectivity Reduction

A frequency-dispersive magnetic material substrate is proposed to achieve the broad bandwidth of metamaterial screens for microwave absorption. Resonance-like ferrites with frequency-dispersive properties at resonant frequencies are applied as substrate. By mixing the multiple types of resonance-like ferrites, the desired bandwidth of frequency-dispersive magnetic material is further broadened. Simulated and measured results show that the proposed metamaterial screen can operate from 7.9 to 14.6 GHz with the reflectivity of less than -10 dB with thickness of only 1.1 mm (0.029 λr,). A figure of merit (FoM) proposed to evaluate the absorption performance of the screen is 20.6 for the proposed screen.