A full-wave analysis of waveguide T-junction with an inductive post

A T-junction with a thick inductive post has been designed for the power combiner/divider of a slotted waveguide array feed. This T-junction is matched by means of a single cylindrical post, placed across the waveguide, parallel to the narrow walls. The design parameters for matching are the position of the inductive post and its diameter. The reflection coefficient of the T-junction with the inductive post is analyzed and minimized, with the diameter of the post taken into account. The analysis is verified by measuring the return loss. The analysis is shown to predict accurately the measured return loss for different diameters of the post. On the basis of this analysis, the position and the diameter of the post are optimized; a return loss below -30 dB is realized over a 5% bandwidth.<>