Design of Frequency-Selective Rasorbers Based on Centrosymmetric Bended-Strip Resonator

Abstract

Two frequency-selective rasorber (FSR) structures using novel centrosymmetric bended-strip resonator (CBSR) are proposed in this paper. Both FSRs consist of the resistive sheet layer and the bandpass FSS layer with an air gap in the middle. The resistive sheet layer is constructed by inserting the CBSR into the center of the resistor-loaded dipole. The CBSR resonates at the transmission band of the bandpass FSS and exhibits infinite impedance, which is used to realize high-transmittance performance at the transmission band. The full wave simulation results show that the transmission band of one FSR is above the absorption band (A-T FSR), while the transmission band of another FSR is below the absorption band (T-A FSR). The transmission band of the A-T FSR and T-A FSR are separately located at 12.76 and 6.08 GHz with 0.66- and 0.13-dB insertion loss, and the corresponding absorption bands with absorption rate >90% are located at 6.10-10.98 GHz and 9.04-15.94 GHz, respectively. The CBSR used in T-A FSR (M-CBSR) is a miniaturized design of the CBSR used in A-T FSR. Comparing with the CBSR structure, the electric length of the M-CBSR's longer side is reduced to about 50%, which is only 12.2% of the wavelength of the transmission band. Two prototypes are fabricated and measured to verify the absorption/transmission performance of the proposed FSRs. The measured results are in good agreements with simulated results, which evidently demonstrates the validity of the proposed design.