SRR异向介质特性研究及其在导波结构中的应用

Fundamental modal properties of split ring resonator metamaterials and metamaterial based waveguiding structures

将SRR异向介质引入导波结构。研究表明:含有SRR异向介质的平行平板波导和矩形波导将出现无截止频率传播和单模传输频带增大的横电波和横磁波。而对于含有异向介质的非辐射介质波导和H波导,纵剖面磁(LSM)波型和纵剖面电(LSE)波型的相速度能够减慢,并且会引起功率流动的增强。另外,LSM波型和LSE波型有时会出现传播常数随频率增高而减小的异常高次模式。利用异向介质的双各向异性效应可以有效减少LSM和LSE波型的高次模漏波现象。尤其当异向介质取单负参数时,高次模漏波将可以被完全抑制。

A rigorous full wave analysis of bianisotropic split ring resonator（SRR） metamaterials is presented for different electromagnetic field polarization and propagation directions. An alternative physical explanation for SRR resonance band gaps is gained by revealing the fact that imaginary wave number leads to the SRR reso- nance. Metamaterial based parallel plate waveguide and rectangular waveguide are then examined to explore the resonance response to transverse magnetic and trans- verse electric waves. Different dispersion properties, such as non-cutoff frequency mode propagation and enhanced bandwidth of single mode operation, come into existence under certain circumstances. In addition, salient dispersion properties are imparted to non-radiative dielectric waveguides and H waveguides by uniaxial bian- isotropic SRR metamaterials. Both longitudinal-section magnetic （LSM） and longi- tudinal-section electric （LSE） modes are capable of propagating very slowly due to metamaterial bianisotropic effects. Particularly, the abnormal falling behavior of some higher-order LSM and LSE modes, eventually leading to the leakage, may appear when metamaterials are double negative. Fortunately, for other LSM and LSE mades, leakage can be reduced due to the magnetoelectric coupling. When the metamaterials are of single negative parameters, leakage elimination can be a chieved.