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Port Excitation of 3D Helical Coil

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Dear Community,

I am trying to simulate an Helical Coil, based upon the example "RF Coil". I am essentially trying to achieve the exact goal as carried out by the RF coil example. First an Eigen analysis and then a frequency study to determine the s parameters.

The 3D coil, is formed from the helix primitive and for the frequency study the surface of it is set to an impedance boundary condition. The eigen study works great and there are no problems there. I cannot get the model to converge for the frequency study with the many port configurations which I have tried.

Attempted Solutions:

I am not sure if a lumped port is suitable when using this geometry as the helix has a circular cross section. I have set up the port similar to that in the example model "rf coil" by using PEC connected to each arm of the coil. Did not converge.

I modified arms of the coil so that their cross section morphed into a rectangular cross section, to recreate a similar geometry as shown in the RF coil section. Did not converge.

I've tried using other port configurations but I just can't get it to work. Such as user defined lumped port and I've also tried the standard "Port" option.

Please could somebody point me in the right direction, as I cannot find anything relevant in the literature. What is the suitable port configuration when using a 3D helical structure such as mine?

I have not meshed the surrounding layers ( I have no problem with this) in the model attached, but everything else is set up. I just need to add the correct ports.

www.dropbox.com/s/2k5tbn6vfpl8u94/Eigen%20%26%20S%20Params%20of%203D%20Helical%20Coil.mph?dl=0

The file size is a fraction over the upload limit.
Kind Regards,
Nyle


0 Replies Last Post Sep 16, 2016, 7:20 a.m. EDT
COMSOL Moderator

Hello Nyle Parker

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