Design of a Quad-Band Wide-Angle Microwave Metamaterial Absorber

We report the design, analysis, fabrication, and measurement of a quad-band microwave metamaterial absorber that exhibits four distinct high absorption peaks at specific resonance frequencies. The proposed structure consists of a metallic hexagonal patch layer on top of a dielectric substrate with a metallic film as bottom layer. The simulation and experimental results show that the absorber presents four distinctive perfect (>90%) absorption peaks up to incidence angle of 40° for both transverse electric and transverse magnetic modes. The results prove that this kind of quad-band absorber has good performance over a wide incidence angle range and is polarization insensitive. Moreover, the experimental and numerical simulation results are essentially in agreement.