基于金属线阵列嵌入的低频宽带电路模拟吸波体设计

Design of a low-frequency broadband circuit analog absorbers based on wire media

由于等效电阻谐振条件限制,传统的单层电路模拟吸波体(CA)结构在低频段不能形成多个谐振点.为了突破这个限制,本文提出了一种金属线阵列嵌入的单层CA结构.该结构在低频段形成了双谐振峰吸收,拓展了吸波频带.采用准静态模型,分析金属线阵列嵌入的单层CA结构内的电磁波的散射.分析结果表明,金属线阵列的嵌入使结构的介质层在低频激发等离子体谐振.在该谐振频率点,结构形成额外吸收峰,该吸收峰和单层CA结构原有的吸收峰一起实现了双峰吸收.实验和FDTD数值计算结果相符合,结果表明该结构在不增加厚度的前提下,扩展了低频段的吸波频段.

A circuit analog absorber （CA） with wire medium is presented. Both the original CA and the structure presented are analyzed. It is shown that original CA cannot have more than one resonant frequency in low frequency band, owing to the limitation by the effective resistance. The presented structure breaks the limitation using artificial plasma resonance, with the wave dispersion in the structure analyzed using the quasi-static model. The experimental results, consistent with simulation results based on the finite-difference time- domain （FDTD） method, show that the structure obtains dual-band absorption, thus broadening the absorption band in low frequency band.