Experimental Characterization of a Singly Loaded E-Plane Waveguide Post by Using a Tunable Coaxial Line

Equivalent-circuit parameters of a singly loaded E-plane waveguide post have been experimentally measured by loading one end of the post with a tunable coaxial line. The resulting structure shows a transmission minimum and a transmission maximum. The positions of the movable short for minimum and maximum transmission have been correlated with the parameters to be measured. It is seen that the errors due to uncertainty in the length measurement can be minimized through the use of a coaxial line with the highest feasible characteristic impedance. Agreement between theoretical and experimental results is satisfactory.