Based On The Crlh Transmission Line Theory And Simulation Of Microwave Resonators

In recent years, an artificial composite material named "Metamaterials" has attracted more and more attention in Solid Physics, Materials Science, Optics and Applied Electromagnetics. It owns important value in actual application, Due to having some specific electromagnetic properties, such as negative permittivity, negative permeability and negative index of refraction. In 2004, T.Itoh introduced the characteristic of Metamaterial in detail according to the idea of metamaterial conformation using transmission line theory, produced the artificial composite right/left-handed transmission line (CRLH-TL) utilizing non-oscillatory microwave elements (Interdigital capacitor and stub inductor), and used it to realize the design of different microwave devices. It makes great sense in the development of electronic integration and microwave communication.The paper first reviews the transmission line theory and the microwave networks technique, and sums up the properties of artificial CRLH-TL and it's physical realization. Then the paper chiefly introduces the situation of designing the microwave resonators using CRLH-TL. Compared with conventional microstrip transmission line resonators, it can be found that the zeroth-order resonator (ZOR) can satisfy better the request which contains the micromation and high performance for the devices in the designing of microwave integrated circuit by analyzing the resonance characteristic and loss mechanism of ZORs. ZORs have better applied outlook in the designing of microwave devices with resonator circuit, such as RF filters, oscillators and so on.The paper chiefly utilizes FDTD numerical computation method, the accuracy of FDTD numerical computation is enhanced by setting perfectly matched layer (PML) absorbed boundary condition and partitioning inhomogeneous adaptive mesh., thesimulation result confirms that FDTD algorithm is useful at calculating this kind of structure model compared with the one of using the method of moments (MoM) in the reference. Then the ZORs structure is adjusted by changing the number of periodic unit, the width of stub inductor, the pair of interdigital capacitor, the position, shape and dimension of the via connected to the ground respectively, it can be found that the resonant frequency of ZORs is affected by the adjusted structure. Two different optimizing modes are given to optimize the structure of ZORs through more theoretical analysis, the FDTD simulation results illustrate that the resonance properties of optimized ZORs are as the same as the former ones. Furthermore, the dimension of optimized ZORs becomes smaller with higher quality factor. At the end, an novel spiral line resonator is proposed, it is confirmed that this resonator has a smaller attenuation, better stop-band characteristic and considerable size reduction in comparison to ZOR through simulation.