Analysis of H-plane waveguide discontinuities using hybrid multimode contour integral and mode matching techniques

A new hybrid method based on multimode contour integral and mode matching techniques will be introduced. It is capable of analyzing any H-plane discontinuity in a rectangular wavegulde. The process is based on segmentation and dividing the structure into key building blocks. We use the multimode contour integral method to analyze the blocks including irregular shape H-plane discontinuities. In opposite to traditional contour integral method, which considers only the effect of dominant mode (TE10) on wave ports, multimode contour integral considers the effect of higher order modes (TEn0) excited by discontinuities on these ports. The mode matching technique will be used to analyze the connecting blocks which can be easily treated by modal expansion. Then the generalized scattering matrix (GSM) of the whole structure can be found by cascading the blocks. The accuracy of our purposed method is validated by comparison with results obtained by other methods.