  In this work, a comparative study of the susceptibility chart in a partially
dielectric-loaded rectangular waveguide and in its equivalent partially
dielectric-loaded parallel-plate waveguide with the same height is performed.
This study shows how the inhomogeneity of the electric field inside the
rectangular waveguide modifies the edges of the multipactor susceptibility
chart with respect to that predicted by the parallel-plate waveguide case.
Moreover, comparisons of the evolution of the population and the trajectory of
the effective electron and the DC field appearing in the waveguide in a point
well inside the multipactor region obtained with both models are performed,
showing some quantitative differences in the multipactor evolution, but a
similar qualitative behaviour is observed.
