Application of MFIE to three-dimensional conducting waveguide transitions of arbitrary shape

By combining the general magnetic field integral equation (MFIE) and the modal expansion technique, an integral formulation suitable for calculating waveguide transitions of arbitrary shape is obtained. For waveguide transitions whose regions are simply connected, the uniqueness of the solution is guaranteed. A numerical solution is obtained by using the method of moments and the conjugate gradient technique. First numerical results confirm the correctness of the method and of its numerical implementation. Good accuracy and convergence are achieved.