谐振频率可调的环状开口谐振器结构及其效应

理论和实验研究表明，开口谐振环(SRRs)中可以激励磁谐振从而实现负磁导率.通过在SRRs结构中引入与其开口边平行的金属短杆设计并制备了新的磁谐振单元，采用波导法系统研究了短杆对SRRs和左手材料的微波透射特性以及左手效应的影响.实验和数值模拟表明：金属短杆和SRRs开口边形成附加电容，导致SRRs开口电容增大从而引起谐振频率降低.随短杆长度l和短杆与SRRs间距d的增大，SRRs谐振频率也随之减小和增加.短杆的加入不影响SRRs的负磁导率特性，改变短杆与SRRs间距d< 关键词： 开口谐振环 金属短杆 调控 左手材料

Tunable split ring resonator and its effect

It has been theoretically and experimentally shown that split ring resonators (SRRs) can be used as a negative permeability medium near its magnetic resonance frequency. In this paper, a new structure for magnetic resonance has been designed by introducing a short wire into the common SRRs. The effects of short wire on the transmission characteristics of SRRs and left-handed metamaterials (LHMs) are experimentally and numerically investigated. The results show that an additional capacitor, formed by short wire and the gap side of SRR, leads to higher capacitance around the gap and lower the resonance frequency of SRRs. The resonance frequency of SRRs decreases with the length of short wire, but increases with the distance between short wire and SRRs. The short wire has no significant influence on the negative permeability of SRR. It is also demonstrated that the left-handed transmission peak, negative permeability, antiresonance frequency of permittivity and negative refractive index of LHMs could be tuned by controlling the distance between the short wire and the SRR.