Coaxial probe modeling in waveguides and cavities

Modeling, design, and sensitivity analysis of probe-excited cavities are presented. The three-cavity-moment method is used to obtain the two-port scattering matrix of the probe-excited semi-infinite waveguide while a novel equivalent circuit is introduced and used as a circuit model for the scattering matrix. A design procedure for probe-excited input/output cavities in waveguide filters is proposed, and a sensitivity analysis is carried out to show the effect of the probe's dimensions on the electrical characteristics of the circuit. Agreement with experimental data is excellent for loosely coupled probe-excited semi-infinite waveguide problems. An example for a 15-GHz-thick iris filter verifies the validity of the proposed design.<>