基于等效电路模型的高频透波频率选择吸波体设计

Design of high-transmittance frequency selective rasorber based on equivalent circuit model

基于等效电路模型分析方法设计了一种高频透波频率选择吸波体,实现了吸波体通带位于其吸波带之上频段的滤波特性.频率选择吸波体的损耗层和带通层分别采用了加载集总电阻的曲折方环单元和十字缝隙单元.仿真结果表明,所设计结构的通带中心频率位于X波段内的9.34 GHz,通带中心频率处的插入损耗小于0.7 dB,-10 dB吸波带为3.0~8.3 GHz.当电磁波斜入射角度小于40°时,所设计结构均保持稳定的传输性能和反射性能.由于频率选择吸波体所采用的周期单元结构的旋转对称性,其传输和吸波性能对入射电磁波的极化方式不敏感.

Based on analysis method of equivalent-circuit model,this paper proposes a high-transmittance frequency selective rasorber(FSR)to realize the filtering characteristics of the rasorber transmission band located at the higher frequency of rasorber.The convoluted square ring elements and cross-like slot elements with lumped resistors are adopted on loss layer and lossless layer of FSR respectively.Simulation results indicate that the central frequency of the designed transmission band is at 9.34 GHz of X band with insertion loss below 0.7 dB,and absorptive band with both reflection and transmission coefficients under-10 dB is from 3.0 GHz to 8.3 GHz.When the oblique incidence angle of electromagnetic wave is less than 40°,the design structure maintains stable transmission and reflection performance.Because of the rotational symmetry of the periodic element structure used in the FSR,its transmission and absorbing performance are not sensitive to the polarization mode of the incident electromagnetic wave.