Dual-polarized frequency selective rasorber with dual absorption bands

A dual-polarized three-dimensional absorptive frequency selective transmission (AFST) structure consisting of bent metallic strips embedded with chip-resistors, and a parallel plate waveguide has been introduced. The structure exhibits two wide absorption bands which flank both sides of the passband, and each absorption band contains two reflection zeros contributing to the wideband performance. An equivalent circuit model is derived to investigate the design concept. A prototype is fabricated and measured, and good agreement between the simulated and experimental results is obtained. In addition, the AFST shows a stable response even for oblique angles and for both TE- and TM-polarizations.