非均匀缺陷环对微波左手材料的影响

以金属铜六边形开口谐振环(SRRs)与金属铜线的组合为结构单元，研究了三维左手材料中的 缺陷效应. 利用电路板刻蚀技术制备了左手材料样品，采用波导法测量了SRRs构成的点缺陷 和线缺陷对左手材料X波段（8—12 GHz）微波透射行为的影响. 实验结果表明，引入不同尺 寸SRRs构成的点缺陷，材料谐振峰强度下降，最多达6 dB，相当于原来的186%，谐振频率 移动，通频带宽在630—720 MHz范围变化；引入不同尺寸SRRs构成三种取向的线缺陷时，材 料谐振峰强度下降，最多达11 dB，相当于原来的34 关键词： 左手材料 缺陷效应

Effect of nonuniform-defect split ring resonators on the left-handed metamater ials

We have investigated the defect effect in three_dimensional (3_D) left_handed metamaterials, consisting of an array of repeated unit cells of copper wires and hexagon split ring resonators (SRRs) on strips of standard circuit board materi al. By measuring the X_band transmission through this metamaterial with differen t point_ and linear_defected SRRs, we find that the resonance frequency, its val ue and passband of transmission peaks, changes markedly. It is suggested that su ch tunable left_handed properties may arise from the symmetry breaking of SRRs i n the metamaterials.