Over the past decades computational electromagnetics tools have become
an indispensable aid for engineers and scientists. Partial Differential
Equation techniques, with the Finite Element method being an example,
are recognised as being the standard approach for the electromagnetic
analysis of closed structures such as waveguide components and cavities.
A major drawback of these techniques results from the fact that they
require a spacesegmentation of the domain under consideration. If
complex geometries or structures with dimensions exceeding few
wavelengths are to be solved, the resulting meshes tend to become very
large, which is undesirable in terms of memory requirements and
computation time. In contrast, a striking feature of the Mode Matching
technique discussed in this thesis is its ability to efficiently solve
the field problem imposed by such structures, provided they can be
decomposed into sub-domains whose spectrum of Eigenmodes is known
analytically. Using the Mode Matching technique, orthogonal expansion of
the yet unknown tangential fields at the interfaces between these
sub-domains is performed, which leads to a system of equations that can
be solved for the Eigenmodes' amplitudes. Several applications such as
waveguide filter design strongly benefit from the Mode Matching
technique's computational efficiency rather than they suffer from the
geometric limitations resulting from the method's quasi-analytical
approach. The present thesis provides a complete treatise of the Mode
Matching technique. While literature has focused almost exclusively on
the method's underlying electromagnetic concept, this work offers
in-depth insights into implementation-related aspects such as efficient
matrix population and proper scattering parameter calculation. To
illustrate the advantages of the Mode Matching technique, the solvers
developed in the scope of this thesis are used to analyse problems from
two fields of application: The analysis of waveguide filters repre
