A rigorous modal analysis of H-plane waveguide T-Junction loaded with a partial-height post for wide-band applications

A rigorous modal analysis (MA) for the H-plane waveguide T-junction loaded with a partial-height conducting post is presented in this paper, The analy sis is based on the classical resonator mode-matching technique for wavegui de junction problems and a novel concept called extended eigenmode function s, The new concept can be used for constructing eigenmode functions of a co mplex resonator region as long as the modal solution for a subproblem is av ailable. Particularly for the T-junction problem, the modal solution for th e two-port in-line waveguide loaded with the post is used. The proposed MA has been extensively verified by a finite-element method software package. Excellent agreement can be observed. Numerical results obtained by the anal ysis reveal that by adjusting the dimension of the loading post, the usable band width of the T-junction for constructing a diplexer can be significan tly expanded. Since the generalized scattering matrix is obtained, the prop osed analysis can be integrated with other available waveguide key building -block models for system analysis.