基于可重构超材料的太赫兹可调带阻滤波器

摘要

A tunable terahertz tri-band bandstop filter based on reconfigurable metamaterials was designed.The filter consists of a movable part and a fixed part,and two parts are both Au-Si two layer structure.The thickness of gold is 0.65 μm,and that of the silicon layer is 25 μm.The movable part is drived by electrothermal driver and its maximum displacement is 5 μm.The movable part is a rectangular ring with different side lengths,and the fixed part is a split-ring-resonator(SRR).Finite integration time domain(FITD) method is applied to analyze the performance of filter.According to the distribution of surface currents,the equivalent circuit models are set up.The surface current distribution shows that the center frequency of the third stopband is generated by the dipole oscillation on the surface of movable part,and the center frequency of the first two stopbands are generated by low frequency dipole resonance and high frequency dipole resonance on the fixed part,respectively.The designed tunable bandstop filter has important application value in the field of terahertz communication and frequency-selective terahertz detection.%设计了一种基于可重构超材料的太赫兹三带可调带阻滤波器.该滤波器各单元均由可动部分与固定部分构成,两部分均采用金-硅两层结构,表层金的厚度为0.65 μm,下层硅的厚度为25 μm.可移动部分由电热驱动器进行驱动,最大位移为5 μm.可动部分为两边长不同的矩形环,固定部分为开口环.用时域有限积分方法研究了滤波特性和频率可调机理,并根据表面电流分布情况,建立了等效电路.由表面电流分布可知,前两个阻带中心频率分别由固定部分的低频偶极子和高频偶极子振荡产生,第三个阻带中心频率由可动部分表面的偶极子振荡产生.该可调带阻滤波器在太赫兹通信和频率选择性太赫兹探测领域有重要应用价值.