A dual‐band metamaterial microwave absorber

A dual‐band metamaterial microwave absorber for X band (8–12 GHz) applications is proposed. A unit cell of the absorber consists of an electric LC (ELC) resonator, a backing ground plate, and an FR4‐epoxy substrate with 0.8 mm thickness. To realize efficient space utilization for the dual resonance, an ELC resonator consisting of asymmetric triangle split‐ring resonators is adopted. Using effective medium parameters extracted from the S‐parameters, the EM behavior is clarified to describe the operating mechanism. The miniaturized dimensions of the unit cell are 8 mm × 8 mm × 0.8 mm. The measured results exhibit two absorptivity peaks stronger than 98.5% and FWHMs of 8.4% and 7.25% at 8.2 GHz and 12 GHz, respectively. Additionally, high absorptivity performance is achieved for EM waves from 0° to 60° regardless of the incident angle.