Analytical model for coupling of waves between a homogeneous medium and a volumetric transmission-line network

In this work, we propose an analytical method to describe the reflection and transmission through a metal waveguide taper, which can be used to couple a transmission-line network with any homogeneous medium. The described method is based on the "step approximation" of the inclined sidewalls and the implementation of a simplified mode matching technique along the separating boundaries. The numerical efficiency of this technique has been found to be quite high and its validity has been successfully confirmed through comparison with simulation data.