A numerical research of the range of normal modes of an open inhomogeneous waveguide with circular cross-section

Background. The aim of the work is to research the range of the problem of propagating electromagnetic waves of an open inhomogeneous waveguide with circular cross-section. Materials and methods. To determine the solution the authors use a variational formulation of the problem. The physical problem is reduced to solving the eigenvalue problem for the system of ordinary differential euqations. To find a numerical solution the Galerkin method is applied using finite piecewise linear basis functions. Results. The authors have developed and realized a numerical method for solving the problem of normal mode propagation in an open inhomogeneous waveguide with circular cross-section, as well as carried out a number of numerical experiments. Conclusions. The suggested numerical method is an efficient way to find an approximate solution to the electromagnetic wave propagation problem.