Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Need to simulate very thin layer with permittivity and permeability tensors

Please login with a confirmed email address before reporting spam

I am simulating an antenna structure in the RF module. Unfortunately, due to 3 dimensions of variability, no 2D models are suitable. Therefore, I am using a 3D solver.

I have an impedance sheet covering a radial waveguide that produces a leaky wave. The impedance sheet has both permittivity and permeability tensors. The simulation is cleanest (i.e. smallest and produces best results) with the transition boundary condition. However, though I can input an anisotropic permittivity, the permeability only allows constant inputs.

Is there a module that has the capability to include permeability tensors in a transition boundary condition? I have not found one yet, with some fairly deep searching. Sans that, can a custom boundary condition be written that allows this?

Other attempts I have tried are making an actual 3D bulk material in place of the transition boundary. This is problematic because the material must be very thin, which greatly complicates the simulation. I am unable to get a thin enough layer.

An alternate approach is to define a current source that is dependant upon impingent fields. However, this requires both electric and magnetic current sources, and as of right now, I havent found a way to implement both on the same boundary.

Thank you,
Jason

1 Reply Last Post Jun 13, 2016, 9:01 a.m. EDT
COMSOL Moderator

Hello Jason Heebl

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.


Please login with a confirmed email address before reporting spam

Posted: 8 years ago Jun 13, 2016, 9:01 a.m. EDT
Hi, I think I can solve your problem.
In the relative permeability selection box, you can select "from material". Then under the material node click the Basic(def) button, select the "relative permeability" and choose the "edit" under the output properties window. There you can set the permeability tensor.
Hi, I think I can solve your problem. In the relative permeability selection box, you can select "from material". Then under the material node click the Basic(def) button, select the "relative permeability" and choose the "edit" under the output properties window. There you can set the permeability tensor.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.