Wide-Angle Ultra-Broadband Metamaterial Absorber with Polarization-Insensitive Characteristics

An ultra-wideband metamaterial absorber is developed, which is polarized-insensitive and angular-stable. Three layers of square resistive films comprise the proposed metamaterial. The optimal values of geometric parameters are obtained, such that the designed absorber can achieve an ultra-broadband absorption response from 4.73 to 39.04 GHz (relative bandwidth of 156.7%) for both transverse electricity and transverse magnetic waves. Moreover, impedance matching theory and an equivalent circuit model are utilized for the absorption mechanism analysis. The compatibility of equivalent circuit calculation results, together with both full-wave simulation and experimental results, demonstrates the excellent performance and applicability of the proposed metamaterial absorber.