Cylindrical post with gap in a rectangular waveguide

The problem of a thin hollow post, of the type often used for semiconductor mounting structures, in a rectangular waveguide is considered for the case where the post has a variable gap located at some position on it. The solution for the reflection coefficient in the waveguide for the case where there is only one propagating mode in the waveguide. A comparison of theoretical results and experimental measurements of the reflection coefficient, as a function of gap size, shows the theory yields a high degree of accuracy