Abstract:
A complete method of moment (MOM) analysis of longitudinal rectangular
waveguide power dividers/combiners using multi cavity modeling technique (MCMT) is
the subject matter of this thesis. The technique replaces all the apertures and
discontinuities of the rectangular waveguide based structures with equivalent magnetic
current densities, so that the given structure can be analyzed using magnetic field integral
equation (MFIE). The magnetic field scattered inside the cavity region due to magnetic
current source is determined by using the cavity Green’s function of the electric vector
potential. The cavity Green’s function has been derived by solving the Helmholtz
equation for the electric vector potential for unit source. The scattered magnetic fields in
the waveguide region due to the presence of the transverse magnetic current densities are
solved by rigorous mode matching method. The main advantage of this technique is that
it is possible to find the electric field across any given aperture, which is either parallel or
perpendicular to the direction of propagation. This helps in extending the study to the
power handling capability of the waveguide structure. Further longitudinal power
dividers/combiners analyzed and designed in this thesis are compact in size and the
output ports are in same plane which is an added advantage for phased array applications.
Mainly, different kind of 1:2 and 1:3 power dividers and combiners are designed and
analyzed in this thesis. In the longitudinal 1:2 power dividers/combiners family
longitudinal E and H-plane power dividers/combiners, folded E and H-plane tee junction
circuits are analyzed. E-plane junctions circuits are not matched to the junction so
matching posts are inserted to the structure to get wide frequency response. Similar
techniques are adapted to H-plane 1:3 power dividers and combiners’ cases. Crosstalk
effect due to fabrication error has also been studied. Algorithms have been developed
using MATLAB for determination of various quantities involved. Computed results
obtained for the above waveguide power dividers and combiners have been verified by
measured data with those of commercially available software simulated data.
