To date, only metallic waveguide filters have been typically used
commercially for microwave applications. These filters have
very reduced insertion losses within their operating frequency
band and their construction is considerably economic. On
the other hand, metallic filters have significant drawbacks,
especially when they are designed for satellite and other spatial
applications, since their weight and size may often be too
high, and due to the lack of atmosphere the Multipactor
effect limits considerably the power that the filters can handle.

New topologies of H-plane waveguide filters loaded with dielectric
resonators significantly reduce the risk of Multipactor
effect between the metallic surfaces, consequently the filter
can handle more power without inducing a Multipactor breakdown. 
Moreover, the dielectric loaded filter weight and
volume can be reduced to half of that of the metallic filters;
they have more thermal stability in high power applications;
and some topologies (i.e. evanescent mode filters) can improve
substantially the out-of-band rejection performance.

The general objective of this Thesis is to develop an analysis tool for the simulation of these topologies. 
The strategy followed for the analysis consists on dividing the device in
simpler building blocks: empty waveguides, steps and sections
of waveguide loaded with the dielectric or metallic posts. The
generalized scattering matrix (GSM) of each block is obtained
by the adequate analysis method, and then all the matrices are
connected by a new and efficient iterative technique that
provides the global GSM of the whole
filter. The analysis of the empty waveguides and the steps is well known from the bibliografy, so the Thesis is focused on the analysis of the sections loaded with the dielectric or metallic posts, and a new accurate and efficient
technique for the analysis of H-plane circular rods in rectangular
waveguides is developed. The method is based on a mode matching
procedure that matches open space and guided waves along a
circular boundary that encloses the non-canonical geometries.
Since the field around the obstacles is expanded using open space
cylindrical modes, a full analytical (and highly efficient) solution
can be obtained for dielectric or metallic circular posts. This
technique can be easily extended to arbitrary geometries of the
H-plane obstacles, though a numerical method should be used to
characterize the obstacle in terms of cylindrical modes and the
efficiency would be significantly reduced.

These innovative techniques have been used in the analysis and design
of several new H-plane filters presented in this Thesis with different topologies, involving
single centered and off centered posts, as well as double post
geometries. The performance of these filters in terms of frequency response, out of band rejection and power handling without risk of Multipactor has been evaluated through the analysis and, sometimes, measurements of the manufactured filters.