用变形差分公式计算波导高阶模的截止频率  

Computation of Cutoff Frequency of the High-order Modes by the Modified Finite Difference Method(FDM)

作　　者：尤丽佳[1] 郑勤红[1] 向泰[1] 张方涛[1] 李琳[1] 胥万松[1] 

机构地区：[1]云南师范大学物理与电子信息学院,云南昆明650092

出　　处：《云南师范大学学报（自然科学版）》2012年第1期52-55,共4页Journal of Yunnan Normal University:Natural Sciences Edition

基　　金：国家自然科学基金重点项目资助(50734007)

摘　　要：对差分法所获的离散差分公式作矩阵变换,使差分离散方程的系数矩阵对于波导的各阶模都是正定的,从而可利用该变形离散方程计算波导各个高阶模的截止频率。编程实例计算了矩形波导、L形波导、对称脊波导部分高阶模的截止频率。计算结果表明:用变形差分公式计算高阶模的截止频率,不仅具有较高的计算精度,而且可以很方便地用于各种复杂截面波导问题的设计与分析。The convergence standard requires that the matrix should be positive definite, while the coefficient matrix obtained by finite difference method（FDM） and related with the high-order mode of waveguide is not satisfied the standard. In this paper, this matrix directly obtained by the FDM is modified and the positive definite condition is satisfied. Representative computational examples, the cut-off frequencies of the high-order modes of, rectangular waveguide, L-shape waveguide,and symmetric ridge waveguide are calculated. The results demonstrate the accuracy and flexibility of the modified FDM.

关 键 词：波导 变形差分公式 高阶模 截止频率 

分 类 号：O441.4[理学—电磁学]