A Dual-Polarized L-S-Band Frequency-Selective Rasorber With Highly Selective Transmission Response

A L-S band frequency selective rasorber (FSR) with a highly selective transmission window in-between two absorption bands is presented. The FSR consists of lossy and lossless frequency selective surface (FSS) layers at the top and bottom substrate layers, respectively, with an air gap in the middle. The lossy FSS comprises a modified Jerusalem cross element loaded with lumped resistors. The lossless FSS layers at the bottom include a second-order bandpass filter made of a square patch and aperture. The simulated results show that the proposed FSR achieves a narrow transmission band from 2.60-2.68 GHz for the insertion loss of less than 1 dB, with an insertion loss of 0.67 dB at 2.6 GHz. The band with reflection coefficients lower than −10 dB covers a lower absorption band from 1.18-2.51 GHz (72.1%) and an upper absorption band from 2.78-3.27 GHz (16.2%). Moreover, the proposed structure is polarization-insensitive and exhibits stable performance against oblique incidences up to 30 deg. In addition, a patch antenna has been integrated with the proposed rasorber, demonstrating its capability to realize a low radar cross-section radiating system while not disturbing the electrical performances of the antenna.