In this paper the discontinuity problems of the junction of two different dielectric rectangular waveguides has been studied, both for two dimensional (2D) and three dimensional (3D) cases. The technique used, is to obtain expressions for the z-directed complex power due to all modes (propagating and non propagating) present at the step junction for a normalized incident field. The expressions for junction parameters like admittance and susceptance have been derived for the structures with step

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... junctions in x direction, in y direction and for the 3D case where the step is both x and y directed. The numerical results have then been computed for different step ratios of these three cases.