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Indexed by:会议论文

Date of Publication:2021-01-10

Page Number:538-543

Abstract:This paper presents a novel frequency selective rasorber (FSR) with high in-band transmission at low frequency and wideband absorption at high frequency. It is synthesized by placing a lossy resistive sheet on top of a lossless bandpass FSS separated by an air spacer. For the resistive sheet, to transmit the in-band signals with low insertion loss (IL), the strip-type parallel LC resonator resonating at the operating band is introduced and loaded between the lossy paths composed of the resistor-loaded circular-loops. As the parallel LC resonator resonates and exhibits infinite impedance, from an equivalent circuit point of view, the current is prevented from flowing through the lossy components, thereby low ohmic loss, that is, low in-band IL is realized. The bandpass FSS that has the same resonance frequency as the parallel LC resonator in the resistive sheet is designed to be a two-layer structure, in which the upper layer is the Jerusalem cross slot array and the lower layer is the capacitive metallic patches. High selectivity characterized by a broader stop-band and faster roll-off is realized with this bandpass FSS due to the addition of the metallic patches, resulting in a significant improvement in absorption performance. Simulated results show that a lower IL of 0.32 dB at 7 GHz, as well as an absorption band at 8{18 GHz with both the transmission and reflection coefficients less than -10 dB, is realized under normal incidence. Meanwhile, the proposed FSR also shows good angular and polarization stabilities under oblique incidence due to its small periodicity and rotational symmetry.