Abstract:Aiming at reducing the bistatic radar cross section and increasing the stealth function of the antenna system, a new two-dimensional hypersurface design method with low absorption and high permeability is proposed. The proposed frequency selective rasorber (FSR) structure is composed of the resistance layer on the upper layer and the frequency selection layer on the lower layer. Two layers of substrate are isolated by nylon bolts and nylon columns to ensure a distance of 11 mm between both substrates. The two layers are designed with the zhong-type structure. In this paper, the principle of equivalent circuit absorption and wave penetration of FSR is analyzed, and the absorption effect of FSR with different resistance values is checked by parameter optimization. By analyzing the current distribution at different frequencies, the penetrating and absorbing functions are explained from the physical level. The simulation results show that the -3dB bandwidth of the transmission band ranges from 9.6 GHz to 12 GHz. The insertion loss is only 0.15 dB at the center frequency of 10.7 GHz of the passband, and the absorption bandwidth ranges from 3.84 GHz to 7.84 GHz, with the relative bandwidth reaching to 69%. The FSR has a smaller unit size, i.e. the unit size is 0.026λ*0.026λ.