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Waveguide Output Port Boundary Condition

The waveguide output port boundary condition models the electromagnetic field that leaves the computational domain through an attached waveguide. Similarly to the Waveguide Input Port Boundary Condition, the waveguide output boundary condition assumes that the radiation that leaves the computational domain corresponds to a well-established waveguide mode with the propagation constant \(\beta\). The corresponding equation for the complex amplitude \(\tilde{\mathbf{E}}\) of the electric field at the boundary of the waveguide output port can be written as

\[ \hat{\mathbf{n}} \times \left(\frac{1}{\mu} \nabla \times \tilde{\mathbf{E}}\right) = j\frac{\beta}{\mu} \hat{\mathbf{n}} \times \left( \tilde{\mathbf{E}} \times \hat{\mathbf{n}} \right), \]

where \(\hat{\mathbf{n}}\) is the unit vector normal to the boundary and \(\mu\) is the magnetic permeability.

To create a WaveguideOutputPortCondition, give a name and the boundary Marker:

condition = WaveguideOutputPortCondition(
    name = "My Waveguide Output Port Condition",
    marker = my_marker,
)

Optionally, you can select the outgoing waveguide mode with the mode_index parameter (default 0, the fundamental mode):

condition = WaveguideOutputPortCondition(
    name = "My Waveguide Output Port Condition",
    marker = my_marker,
    mode_index = 1,
)

Usage Examples