Application of the generalized spectral-domain technique to the analysis of rectangular waveguides with rectangular and circular metal inserts

The generalized spectral-domain (GSD) technique, which was previously developed and tested for some special cases by the authors (see ibid., vol.37, p.1924-32, 1989), is applied to the analysis of rectangular waveguides with rectangular and circular metal inserts. These include conventional ridge waveguides, circular-ridge waveguides, and rectangular coaxial lines, with either rectangular or circular inner conductors. The numerical results show that a previously published description of the edge behavior of the electromagnetic field is incomplete. A constant term must be added to the expansion of the magnetic field component which is parallel to the edge. Excellent agreement with other published analysis data is achieved, with a drastic reduction of CPU time for the conventional ridge waveguide. The accuracy of the results is demonstrated by two- and three-dimensional plots of the field distributions