High-Selectivity Band-Absorptive Frequency-Selective Rasorber

This letter introduces a 3-D dual-polarized band-absorptive frequency selective rasorber (FSR) with a sharp pass-to-absorb transition property. The FSR with high selectivity is constructed by a composition made by a lossy layer and a band-stop layer. The working mechanism and the effectiveness of the FSR are analyzed through the equivalent circuit model. The 3-D unit cell is detailed, and a prototype is fabricated and measured in experiments. The proposed FSR possesses a pass-band below 3.02 GHz and an absorption band spanning from 5.37 GHz to 8.59 GHz, exhibiting a sharp spectral transition with a 1.78 FRap factor. The FSR is lightweight, mechanically robust and cost-effective, which is promising in stealthy radome applications for wideband UHF antennas.