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论文类型：期刊论文

发表时间：2012-10-01

发表刊物：APPLIED MATHEMATICAL MODELLING

收录刊物：SCIE、EI、Scopus

卷号：36

期号：10

页面范围：4797-4809

ISSN号：0307-904X

关键字：Scaled boundary finite element method; Quadruple ridged square waveguide; Corner-cut ridges; Cutoff wave number

摘要：This paper describes the development of an efficient semi-analytical method, namely scaled boundary finite-element method (SBFEM) for a quadruple corner-cut ridged square waveguide. Thinking about its symmetry, only a quarter of its cross-section needs to be considered and divided into a few sub-domains. Only the boundaries of the sub-domains are discretized with line elements leading to great flexibility in mesh generation. The singularities in the re-entrant corners are represented analytically by locating the scaling center in those points. Variational principle approach is presented to formulate the basis SBFE equations for the sub-domains. Then, an equation of the 'stiffness matrix' on the discretized boundary is established. Finally, by using the continued-fraction solution and introducing auxiliary variables, a generalized eigenvalue equation with respect to the cutoff wave number is obtained without introducing an internal mesh. Numerical results are presented to verify the accuracy and efficiency of the present technique. Variations of the cutoff wave numbers of the dominant and higher-order modes for both TE and TM cases with the corner-cut ridge dimensions are investigated in details. Simple approximate equations are found to accurately predict the cutoff wave number of TE20U, TE22, TM11 and TM13L modes. The single mode bandwidth of the waveguide is also calculated. (C) 2011 Elsevier Inc. All rights reserved.