Analysis of Quadruple Corner-Cut Ridged Elliptical Waveguide by NURBS Enhanced Scaled Boundary Finite Element Method

The scaled boundary finite element method(SBFEM) is a semi-analysis method, combing the advantages of method and method. However, in solving quadruple corner-cut ridged elliptical(QCRE) waveguide, traditional SBFEM employ Lagrange polynomials as basis functions which leads to curved boundaries cannot be exactly represented continuity order across low. In this paper, non-uniform rational B-spline (NURBS) enhanced firstly extended solve QCRE can describe boundaries, reduce spatial dimensions by one obtain analytically results radial direction. According its symmetry, only quarter elliptical waveguide needs simulated subdivided into several subdomains. straight subdomains are described discretized NURBS functions, respectively. side-face do not need discretized. Then, governing equation eigenvalue problem derived based on vibrational principle coordinate transforming. Finally, generalized respecting cut-off wave numbers established introducing dynamic stiffness employing continued fraction solution. Numerical verify high computational efficiency accuracy with describing boundaries. influence modes single-mode bandwidth investigated details.