Compact Ultra-Thin Seven-Band Microwave Metamaterial Absorber Based on a Single Resonator Structure

In this paper, we present the design, simulation, measurement and characterization of a seven-band polarization-insensitive and wide-angle metamaterial absorber (MMA) in the microwave frequency region. The unit-cell structure of the designed MMA is composed of a single closed-meander-wire resonator structure placed over a metal ground plane by a dielectric substrate. The simulated results exhibit that the proposed MMA has high-level absorption of over 90% at seven distinct resonance frequencies, which agree reasonably with experiment. Simulated electric field distributions reveal that the observed high-level absorption mainly originates from higher-order electric resonance response. Simulated absorbance under different angles of polarization and oblique incidence indicate that the high absorption of this MMA can be kept stable for both transverse electric and transverse magnetic waves. Furthermore, the influences of geometric parameters of the unit-cell structure on absorption properties of the MMA were also studied numerically. In addition, this proposed MMA has good performances of thinner thickness, polarization-insensitive and wide-angle properties, which has many potential applications such as detection, imaging and sensing.