基于阻抗匹配条件的树枝状超材料吸收器

基于树枝状金属结构单元的电磁谐振特性,设计了一种双面大小树枝状结构的超材料吸收器,该结构分别是正面二级树枝及正对的背面三级树枝.通过仿真模拟设计了不同的阻抗匹配方式,调节相应的结构参数,找到了阻抗匹配对吸收特性的影响.在最佳的阻抗匹配条件下,得到最大吸收率.实验测量表明,阻抗匹配条件下双面大小树枝模型可以实现90.01%吸收率.增加样品层数可以有效的增加吸收率,3层样品就可以达到99%以上的吸收率,实现工程意义的完美吸收.

Dendritic metamaterial absorber based on the impedance matching

Based on the electromagnetic resonant characteristic of the metallic dendritic cells, we present a metamaterial absorber (MA) composed of periodic array of double dendritic cells. The unit cell of the absorber is composed of two metallic elements on the substrate, a two-level dendritic cell and a three-level dendritic cell are located on each side separately. Designing different impedance matching conditions, the effect of impedance matching on the absorptivity is found. The experimental results show that a maximum absorptivity of 90% can only occur when the MA layer is impedance-matched to free space. At the same time, increasing the number of MA layers can effectively enhance the absorptivity. For 3 layers, the absorptivity above 99% can be obtained, that is to say, a perfect MA is realized in the engineering sense.