Efficient Pole Expansion of the Generalized Admittance Matrix Representation of Planar Waveguide Junctions

In this paper, the fast and accurate wideband modeling of planar waveguide junctions in terms of a generalized admittance matrix representation is addressed. For these purposes, an integral equation technique providing a pole expansion of the cited admittance matrix is outlined, thus widely reducing the frequency dependant operations. A convergence study of this novel algorithm has been first performed, and then it has been successfully applied to the full-wave analysis of a real filter involving planar junctions between rectangular waveguides.