Dual-Polarized Broadband Band-absorptive Frequency Selective Rasorber

In this paper, a dual-polarized broadband band-absorptive frequency selective rasorber (FSR) is proposed. The band-absorptive FSR exhibits a wide absorption band; meanwhile it is almost transparent to the incident electromagnetic (EM) waves at the frequencies below the absorption band. The FSR is comprised of a lossy layer and an absorptive transmission/reflection surface (ATRS). The lossy layer is realized by a square loop loaded with lumped inductors and resistors. The ATRS is different from the conventional reflective surface - it is comprised of two lossless square loops and one lossy square loop. Those loops are all achieved by loading lumped elements. Simulated results of the FSR is shown in the paper. It exhibits a broad absorption band from 4.02 GHz to 9.34 GHz (79.64% fractional bandwidth), while the cut-off frequency of the passband is 905 MHz ( |S
₂₁
| ≥ -1 dB).