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Using Numeric Ports and Boundary Mode Analysis

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Hello!

I have a few questions regarding using numeric ports.

I have a problem where I have a waveguide with a square cross section. As a result, I can generate two modes with the same effective mode index, one with Efields that are mostly in the x direction, and one where the Efields are mostly in the y direction.

Now, in a 3d model, I am trying to launch a specific mode using boundary mode analysis from either end of this waveguide. However, while the effective mode numbers are the same, it should make a difference whether I launch two modes where the E fields are oriented the same direction, or two modes from either end where the Efields are mostly perpendicular to each other...

1) Is it possible to select the specfic mode I want to launch that I find using boundary mode analysis at the numeric port? 2) Is it possible to select a specfic mode for a port if there are two that are the same effective mode index... 2) Is it possible to plot the fields for the mode that is used to launch the mode at the port? I know you can chose the solution set, but I can't seem to find which variable to plot to plot the fields for the solution set of each of the boundary mode analysis.



4 Replies Last Post Nov 21, 2017, 1:42 p.m. EST
Sergei Yushanov Certified Consultant

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Posted: 7 years ago Oct 3, 2017, 3:18 p.m. EDT

Cheng-Ming,

  1. The two modes are very close but they are not the same. You can use "Full Precision" option in the "Global Evaluation" to see the difference, as shown in the attached table.

  2. There are predefined variables from the Boundary Mode Analysis step which can be used to visualize propagating modes for each effective index, as shown in the attached images.

  3. To lunch specific mode, just use full precision of the effective index, as illustrated in the attached mph file.

Regards,

Sergei

Cheng-Ming, 1. The two modes are very close but they are not the same. You can use "Full Precision" option in the "Global Evaluation" to see the difference, as shown in the attached table. 2. There are predefined variables from the Boundary Mode Analysis step which can be used to visualize propagating modes for each effective index, as shown in the attached images. 3. To lunch specific mode, just use full precision of the effective index, as illustrated in the attached mph file. Regards, Sergei


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Posted: 7 years ago Oct 3, 2017, 6:44 p.m. EDT

If you have a square metallic waveguide, you can use an analytic port and select TE01 or TE10.

If you need to use numeric ports, you can also introduce a slight asymmetry to break the degeneracy of the two orthogonal modes.

If you have a square metallic waveguide, you can use an analytic port and select TE01 or TE10. If you need to use numeric ports, you can also introduce a slight asymmetry to break the degeneracy of the two orthogonal modes.

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Posted: 7 years ago Oct 5, 2017, 3:44 p.m. EDT

Thank you, will give both suggestions a shot.

Thank you, will give both suggestions a shot.

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Posted: 7 years ago Nov 21, 2017, 1:42 p.m. EST

As a heads up, I just tried downloading and the .mph file is downloading as a zip file.

I renamed the .zip to .mph and voila, it now opens.

Guess that explains what the structure is of an mph file :-)

As a heads up, I just tried downloading and the .mph file is downloading as a zip file. I renamed the .zip to .mph and voila, it now opens. Guess that explains what the structure is of an mph file :-)

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