To source a waveguide with one or more modes, apply a wave port to the end of the waveguide. See the section on symmetry planes for an example of using symmetry with wave ports on waveguides. When sourcing a waveguide with a wave port, only the number modes requested in the port properties are sourced at the port, and only these outgoing modes are matched at the port. If additional modes are present in the waveguide, as can result from reflections or other feeds, then these outgoing modes are terminated at the port with a perfect magnetic wall boundary condition.
The following image shows a short section of waveguide with a wave port applied to either end and a PEC impedance boundary condition is applied to all other surfaces, shown in green.
This structure models the transition between a rectangular waveguide and a circular waveguide. The waveguide makes up the entire simulation domain.
You can also use waveguides to feed a larger structure. The next image shows a dielectric waveguide that feeds a larger simulation domain. This is a dielectric waveguide with PEC applied to all four sides.
In this case, the waveguide extends outside the main enclosure, but this is not required. In the following image, the waveguide has been terminated on the geometry boundary.
When used with a waveguide, the port plane only extends as far as the waveguide boundaries. The port mesh is much smaller than the side of the geometry.
Finally, you can terminate the waveguide inside the geometry.
The port mesh is again limited to the end of the waveguide. In this scenario, the port solution is sourced into the waveguide, and the no other fields are sourced from this port. On the outside of the waveguide, the port behaves like a PEC cap at the end of the waveguide.
Request more than one mode in the port definition to obtain results for multiple waveguide modes.