Equivalent Circuits for Gap- and Coax-Excited Circular Posts in Rectangular Waveguide

Equivalent circuits are presented for gap- and coax-excited circular posts in rectangular waveguide. These equivalent circuits, which are derived from previously published analytical results that have been shown to accurately predict the gap (or coax) input admittance without the need for empirical factors, have a common form, many common terms relating to the post and its position, and specific terms related to the gap (or coax) excitation. Numerical and other aspects are also briefly discussed.