3       Circular Waveguides

Waveguides can be simply described as metal pipes. Depending on their cross section there are rectangular waveguides (described in separate tutorial) and circular waveguides, which cross section is simply a circle.

This tutorial is dedicated to basic properties of circular waveguides. For properties visualisation the electromagnetic simulations in QuickWave software are used.

All examples used here were prepared in free CAD QW-Modeller for QuickWave and the models preparation procedure are described. All examples considered herein are included in the QW-Modeller and QuickWave STUDENT Release installation as both, QW-Modeller and QW-Editor projects.

The following topics are included:

• Cutoff frequency

• Mode TE₁₁

• Mode TM₀₁

The model preparation procedure in QW-Modeller is described in the following chapter:

·      Project preparation cir - a circular waveguide filled with air, excited with a fundamental TE₁₁ mode and terminated with a load port matched to the waveguide.