超材料谐振子间的电耦合谐振理论与实验研究

通过将两个金属开口环谐振器口对口地放置, 实现了超材料谐振子间的电耦合谐振. 对电耦合谐振的微波等效电路进行了理论分析和数值计算, 结果表明耦合后的超材料谐振子能产生两个谐振频率, 其中一个随耦合强度的增加逐渐向低频方向移动, 而另一个固定在单谐振子的谐振频率处不变. 微波透射谱的实验测试和电磁仿真结果表明, 两个谐振峰随耦合强度的增加分别向低频和高频方向移动. 分析表明: 低频谐振峰的位置主要是由超材料谐振子间的电耦合强度决定的; 高频谐振偏离单谐振子的谐振频率主要是由不可避免的磁耦合引起的, 而且在耦合间距越小时磁耦合影响越大. 提出的基于超材料谐振子间的电磁耦合实现的双频谐振及其可调性极大地增加了超材料的设计与应用空间.

Theoretical and experimental study of the electric resonant coupling between two metamaterial resonators

In this paper, we realize the electrically coupled resonances between two metamaterial resonators based on two metal split-ring resonators gap-to-gap placed. The theoretical analysis and numerical calculation of the microwave equivalent circuit of the electrically coupled metamaterial resonators are performed. The results show that there are two resonance frequencies produced by the two coupled metamaterial resonators. For the two resonance frequencies, one gradually shifts towards the lower frequency with the coupling strength increasing, while the other is fixed at the resonance frequency of the single metamaterial resonator. The measured and simulated results of the microwave transmission spectra show that the two resonance peaks move respectively towards the lower and higher frequency with the coupling strength increasing. The analysis shows that the lower resonance frequency is mainly determined by the electrical coupling strength between the two metamaterial resonators, and the difference between the higher resonance frequency and the resonance frequency of the single resonator is mainly caused by the inevitable magnetic coupling between the two resonators. Moreover, the smaller the coupling space, the greater the influence of magnetic coupling is. The proposed dual resonance property and its tunability based on the electromagnetic coupling between the two metamaterial resonators greatly enhance the scopes of the design and application for metamaterials.