Analysis and modelling of a coaxial-line/rectangular-waveguide junction

The analysis of a commonly used coaxial-line/rectangular-waveguide junction, formed by the coaxial line entering the broad wall of the waveguide, is outlined. The theory is based on a model closely related to the physical situation and does not require the use of empirical factors. Numerical results can be evaluated directly from the theoretical expressions, and aspects of such evaluation are briefly discussed. Extensive comparison of theoretical and experimental results has shown the analysis to be very accurate. An equivalent circuit for the junction, applicable to the case where the TE10 mode is the only propagating waveguide mode, is also reported.