具有中远红外双阻带特性的频率选择表面设计

Frequency selective surface design of mid-and far-infrared double stopband

为实现覆盖中、远红外两个大气窗口的低透射率,采用六边形环复合“单钺”型短臂与十字结构共振器相结合的思路,设计了一种可调节的、“双环—双屏”三明治结构的频率选择表面。CST电磁软件仿真结果表明,在3~5μm,8~14μm两个红外大气窗口内的平均透射率低于1.9%,可以对中、远红外电磁波有较好的抑制传输效果,并且有优越的偏振稳定性和入射角度稳定作用;通过利用表面电流分析法与等效介质原理法,以不同的角度阐述了频率选择表面结构的滤波机理。并通过仿真计算的方式,探究出电介质层属性与单元结构参数对频率选择表面的滤波效果有较大影响,研究结果对后续实验有重要的指导作用。

In order to realize to cover mid-and far-infrared atmospheric windows,an adjustable,low transmission rate frequency selection surface is designed by combining the hexagon ring and"single tomahawk"with the cross resonator.The simulation results with CST electromagnetic software show that the average transmission rate is lower than 1.9%in the two infrared atmospheric windows of 3~5μm and 8~14μm.By using the method of surface current analysis and equivalent medium theory,the filtering mechanism of frequency selective surface is expounded from different aspects.By means of simulation calculation,it is found that the dielectric layer properties and unit structure parameters have a great impact on the frequency selective surface filtering effect;the research results have an important guiding effect on the following experiments.