Ultra-Thin Dual-Band Polarization-Insensitive and Wide-Angle Perfect Metamaterial Absorber Based on a Single Circular Sector Resonator Structure

We present a simple design for an ultra-thin dual-band polarization-insensitive and wide-angle perfect metamaterial absorber (PMMA) based on a single circular sector resonator structure (CSRS). Both simulation and experimental results reveal that two resonance peaks with average absorption above 99% can be achieved. The dual-band PMMA is ultra-thin with total thickness of 0.5 mm, which is < l/38 with respect to the operation frequencies. The surface electric field and current distributions of the unit-cell structure reveal the physical picture of the dual-band absorption. Numerical simulations demonstrate that the PMMA could retain high absorption level at large angles of polarization and incidence for both transverse electric (TE) and transverse magnetic (TM) modes. Furthermore, the absorption properties of the PMMA can be adjusted by varying the geometric parameters of the unit-cell structure.