MODELING OF MICROWAVE DEVICES USING HIGH-FREQUENCY ELECRTOMAGNETIC COUPLINGS IN MULTILAYERED AND MULTICONDUCTOR TRANSMISSION LINES

本研究的目的是利用全波耦合模理论对多层多导体传输线的微波器件进行建模。主要研究成果如下：1.利用基于互易定理的耦合模理论，建立了多层多导线的传输线方程。利用所提出的传输线方程，给出了多端口耦合微带线系统电路参数的计算公式。对不同耦合微带线结构的电路参数进行了计算，验证了公式的正确性。给出了分析耦合微带谐振器谐振频率的时间域耦合模方程。利用该方程研究了任意取向双耦合微带谐振器的谐振特性。利用广义互易关系和各向异性介质中导向场的对称性，提出了磁化铁氧体衬底上多导体传输线的耦合模理论。所得到的耦合模方程与介质衬底上多导线的耦合模方程的形式相同。应用该方程分析了磁化铁氧体衬底上两条耦合微带线的非互易特性。提出了一种适用于芯区和包层区折射率差较大的耦合介质波导的新型耦合模形成方法。用该公式分析了NRD导轨联轴器的耦合特性。

The purpose of this research project is to investigate a modeling of microwave devices using the full-wave coupled-mode theory for multilayered and multiconductor transmission lines. The main results of the research are summarized as follows :1. Using the coupled-mode theory based on the reciprocity theorem, novel transmission-line equations have been proposed for multilayered and multiconductor lines. The formula to calculate the circuit parameters of multiport coupled-microstrip line systems has been presented using the proposed transmission-line equations. The circuit parameters in various coupled-microstrip line structures were evaluated and the validity of the formula was confirmed.2. The coupled-mode equations in the time domain has been presented for analyzing the resonance frequencies of coupled microstrip resonators. The equations have been applied to study the resonance characteristics in two-coupled microstrip resonators with arbitrary orientation.3. The coupled-mode theory for multiconductor transmission lines on a substrate of magnetized ferrite has been presented, using the generalized reciprocity relation and the properties of symmetry for the guided fields in an anisotropic medium. The resulting coupled-mode equations have the same form as those obtained for the multiconductor lines on a dielectric substrate. The equations have been applied to analyze the nonreciprocal properties of two-coupled microstrip lines on the magnetized ferrite substrate.4. A novel coupled-mode formation applicable to coupled dielectric waveguides with a large refractive-index difference between core and cladding regions has been presented. The formulation was used to analyze the coupling characteristics of an NRD-guides coupler.