A new class of eigenfunction expansion methods for fast frequency-domain analysis of waveguides

This paper presents a new class of algorithms for a fast calculation of dispersion characteristics in inhomogeneously loaded strictly bidirectional waveguides. The algorithms use the method of moments to convert the wave equation to a matrix eigenvalue problem using, as a basis, a set of known solutions determined for a few selected points from the /spl omega/-/spl beta/ diagram. Depending on the choice of points for the basis and the testing functions, several algorithms are derived, each leading to extremely simple expressions for the calculation of the matrix elements.