基于分形结构的太赫兹超材料吸波体  

Terahertz metamaterial absorbers based on fractal structures

作　　者：杨娴[1] 张建民[1] 

机构地区：[1]陕西师范大学物理学与信息技术学院,陕西西安710062

出　　处：《陕西师范大学学报（自然科学版）》2013年第1期32-35,共4页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51071098)

摘　　要：基于分形结构在太赫兹频段设计了一种超材料吸波体,发现该吸波体出现双频点吸收现象.仿真研究了衬底厚度对吸波体吸收率的影响,调节衬底厚度可以实现吸波体与自由空间的近似阻抗匹配.第一谐振点A在衬底厚度为5.4μm时的吸收率最高,第二谐振点B在衬底厚度为1.4μm时的吸收率达到99.9%.随着分维数的增加,谐振频点B逐渐向高频移动,吸收效率几乎保持不变.仿真结果表明,通过调节分维数,可以设计不同频点的吸波体.对双层结构和三层结构进行仿真优化,设计了宽频带吸波体.A metamaterial absorber based on fractal structure is designed in terahertz regime. Dual-band absorptions are presented. The influence of substrate thickness on absorptivity is investigated through numerical simulation. With regulation of substrate thickness, impedance matching between the absorber and free space is approximately achieved. When substrate thickness is 5.4 μm, the reflectivity of the first resonant point A is low, but the absorptivity is high. When substrate thickness is 1.4μm, the absorptivity of the second resonant point B reach 99.9%. With the increase of fractal dimension, point B moves to high frequency, but its absorptivity remains. Simulation results show that the absorbers with different resonant frequencies can be designed by adjusting the fractal dimension. With simulation and optimization of double-layer and triple-layer structures, the broadband absorbers are also designed.

关 键 词：超材料 太赫兹 分形 宽频带 

分 类 号：O441.6[理学—电磁学]