含螺旋单元频率选择表面的宽频带强吸收复合吸波体

设计和制备了含螺旋单元频率选择表面吸波片的三层复合吸波体,上层和下层均为磁性吸波片,中间层为带缺口的螺旋单元频率选择表面.复合吸波体在总厚度分别为1.4,1.7和2.0 mm时,其反射率在-10d B以下的频带宽度分别达到了9.29,6.69和7.11 GHz,与不含有频率选择表面的吸波体相比较(其他参数相同),-10d B以下反射率带宽分别提高了159.5%,69.3%和129.4%,复合吸波体在总厚度低于吸波体时,也取得了更好的反射效果.带缺口圆螺旋单元的频率选择表面嵌入吸波体中,引入了额外的吸收频带,拓宽了吸波体的反射率频带宽度.仿真分析表明嵌入频率选择表面能够改善吸波体的阻抗匹配性,进而影响其反射率.

Composite absorber of broadband and high attenuation with spiral frequency selective surfaces

In this paper, a three-layer composite absorber with a split-spiral frequency selective surface layer clamped by two traditional absorber layers, is designed. The 1.4, 1.7 and 2.0 mm thick composites reach, respectively, the bandwidth values of 9.29, 6.69 and 7.11 GHz at a reflectivity lower than the -10 dB level, whose operating bandwidths are increased by 159.5%, 69.3% and 129.4% compared with those of the traditional absorbing sheet without frequency selective surface (under otherwise identical parameters). Further, the paper shows that the thinner composite sheet can have more excellent performance in reflection than the absorb sheets. The split-spiral frequency selective surfaces generated multiple resonance can be used to generate additional absorption band. The simulation results show that the embedded frequency selective surface improves an impedance matching between absorber with the free space, which changes the reflection of the absorbing sheet.
Keywords： electromagnetic absorber frequency selective surfaces electromagnetic composite absorber