Reactance of hollow, solid, and hemispherical-cap cylindrical posts in rectangular waveguide

An accurate experimental technique is employed to determine the reactance of three commonly used symmetrical waveguide discontinuities: cylindrical posts with hollow, solid, and hemispherical-cap ends, and a useful data set is presented. Length adjustment factors are derived for the case of symmetrical excitation that relate the reactance of each post form. When used in conjunction with an existing analysis, it is shown that very accurate results can be predicted for the reactance of solid and hemispherical-cap posts.