T-Equivalent Circuit Parameters of a Variable-Length Cylindrical Post in a Rectangular Waveguide

A simple expression for the series reactance of a solid variable-length cylindrical post in a rectangular waveguide is determined from an approximate field analysis. Results are shown to be in excellent agreement with experimental measurements. When used in conjunction with an existing analysis for determining the shunt reactance, it is shown that accurate results can be calculated for the complete T-equivalent circuit.