Frequency selective rasorber based on cross bend resonators for wideband transmission and absorption

Abstract

The wideband absorption and transmission of frequency-selective rasorber (FSR) remain a persistent challenge in the application of radar devices. In this article, a novel high performance wideband FSR design based on cross bend resonators (CBR) was proposed. The FSR consists of an upper absorption lossy layer, which offers broad absorption and transmission bands, and a lower bandpass frequency-selective surface (FSS) that enables a highly selective transmission of incident electromagnetic wave. Full wave simulation results showed that this novel design achieves an absorption bandwidth of 83.7% with more than 90% absorptivity in the frequency range of 5.2-12.7 GHz. Furthermore, the passband's fractional bandwidth (FBW) for the insertion loss (IL) less than -3 dB is 33.9%, ranging from 14.9 to 21 GHz, with the minimum IL recorded at 0.69 dB at 17.7 GHz. To further verify the proposed method, a prototype FSR with 10×10 units of 120 mm×120 mm was fabricated and the performance of the FSR was tested. The experiment results were in good agreement with the simulated results, and it showed a significant monostatic radar cross-section (RCS) reduction in the frequency range of 5.3 GHz to 18.3 GHz compared with a metallic plane of the same size.