用FDTD分析波导和谐振腔本征值问题及模场仿真

【作者】 王秀玲；

【导师】 郑勤红；

【作者基本信息】 云南师范大学 ， 无线电物理， 2008， 硕士

【摘要】 本文主要开展FDTD方法在波导和谐振腔问题中的应用研究,基于FDTD法结合Matlab编写了相关计算程序,对多种场域条件下的传输线、波导和谐振腔进行了模拟计算,分析了其相关物理参数和模场特性。主要工作如下：(1)介绍了各类电磁场问题的常用求解方法,对FDTD的发展历程及其广泛应用进行了综述性介绍。介绍了FDTD算法的基本概念、基本原理及主要实施过程。结合文献和自己编程计算经验,阐述了FDTD方法的数值稳定性和数值色散对空间网格和时间网格的要求、介质分界面的处理方法、吸收边界的设置方法以及激励源的选择与设计。(2)用FDTD法编程实例计算了T形分隔波导、矩形同轴传输线、部分介质填充的矩形波导本征值问题,并把计算结果与相关文献的报道结果进行了比较,证明了方法和所编程序的正确性：编程计算了至今尚未见报道的十字形截面方形同轴线以及部分介质填充的十字形截面的方形同轴线的本征值问题。编写相关的程序对十字形截面的方形同轴线、部分介质填充的十字形截面的方形同轴线的TE主模场进行了仿真。(3)用FDTD法编程计算了矩形谐振腔的本征值,对其模场分布进行了仿真,并用电磁理论分析了模拟结果的正确;编程计算了部分各向异性介质填充矩形谐振腔的本征值并进行了模场仿真。更多还原

【Abstract】 In this paper, research work on the application of FDTD method in waveguide and resonant cavity has been carried out. The relative programs are made based on FDTD and the Matlab. The electromagnetic fields of the waveguide and resonant cavity in different conditions have been simulated and calculated. Also some important physics parameters and the mode fields are calculated and simulated.(1) Various methods to analyze electromagnetic field problems are introduced. The development and applications of FDTD method have been summarized. The basic conception and main procedure to put in practice is presented.The requirement for the time interval and Courant condition for stability of FDTD, method handing of different boundary and optimization design excitation sources in making programs, are discussed detailedly.(2) Based on FDTD method, programs to calculate eigenvalues of T-septate rectangular waveguide, rectangular coaxial transmission line and rectangular dielectric-rod loaded waveguide are made. The results agreed well with that of the reported in the literature. A conclusion that this method and the program are effective and an excellent precision has been obtained. As a application, eigenvalues of the unreported transmission line consisting of crisscross and rectangular outside conductors were calculated. Sequentially, eigenvalues of dielectric-loaded transmit-ssion line consisting of crisscross and rectangular outside conductors is computed. Also, their electromagnetic fields of TE dominant mode are simulated.(3) The electromagnetic field in rectangle resonant cavity is simulated and its eigenvalue is calculated by the program. Also the results and correctness are discussed based on electromagnetic theory. Then, the programs to calculate the eigenvalue and to simulate the electromagnetic field of anisotropic medium loaded rectangle resonant cavity are made.更多还原