Efficient CAD of generalized coaxial probes in rectangular waveguide using the 3D BI-RME method

An efficient full-wave method based on the 3D BI-RME (Boundary Integral-Resonant Mode Expansion) technique for the accurate design of generalized probe-excited rectangular waveguides is presented. The flexibility of the developed CAD tool allows to analyze two common configurations frequently used in modern coaxial-fed microwave devices: conventional and disc-ended coaxial probe excitation. This last configuration is used to drastically improve the electrical response of the classical coaxial probe excitation. Moreover, the influence of the distance from the probe to the waveguide shortcircuit is also discussed, and it is shown that it plays a very important role in the design of probe-excited rectangular waveguides. The proposed approach is fully validated by comparing the obtained numerical results with theoretical and experimental data extracted from the available technical literature.