A full-wave modal analysis of inhomogeneous waveguide discontinuities withboth planar and circular cylindrical boundaries

A full-wave analysis of an inhomogeneous waveguide region with both planar and circular cylindrical boundaries is presented in this paper. Circular cy lindrical modal functions are used to represent the fields. Field matching on the planar walls and apertures is rigorously achieved by the finite plan e-wave series expansion of each modal field, whereas the addition theorem f or cylindrical waves is used for rigorous field matching on the circular cy lindrical boundaries. Numerical results are given for rectangular waveguide s with 90 degrees bends and rounded outer corners.