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Port impedance in CST MWS

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pewang

pewang

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Hi,all friend
When I simulating some small volume coaxial component in MWS,if I use symmetry boundary,port impedance acurracy very low,even I improve severl times mesh node.When I cancel symmetry boundary,I can get a close result,but this will lead long simulate time.Does anyone know how to control port impedance accuracy?
When I check port info,I found calculate mode accuracy can control.But when do transit solve,I dos'nt know how to control port impedance calculation accuracy.
Thanks!
 

Hi, pewang!

Please can you post your design here? Will be more telling.
"symetry boundary" you mean electric or magnetic wall?
We will try to solve it, I ever haven't problem with port impedancies..
Rgz,
Eirp
 

My design is an coaxial SMA connector.I use XZ and YZ plan as magnetic wall.So software simulate only quarter of model.I have checked mesh node at port,it is very spares.
Per the model dimension,use impedance equation,port impedance should be 50 ohm so far,but CST calculate only 48.3ohm.Also result very unstable,somtimes it calculate result is 53 ohm.My mesh node setup is per wavelength 30 node,I think it enough.
But when I check port info(right click on port),set mode accuracy to 0.1%,and calculate port mode,CST can give good result after several pass.
But when you solve the whole model,CST solve mode port impedance only one pass.
 

Sparse mesh at port plane can be a problem.
Try to refine only dielectric material between inner and outer conductor:

1) Turn on mesh view
2) Select dielectric under its layer
3) Go to: Edit --> Mesh properties
4) Maximum mesh step width: Change numbers Dx and Dy (transversal coord) to i.e. 0.1. After Apply you'll see mesh refined in port critical location

With Dx=Dy=0.1 My result of coax (designed to be 50Ohm) is Z0=50.0161 Ohm.

best regards,

Eirp
 

Dear Pewang,

Perhaps my message is coming to this discussion a little
late, one year delay... Anyway, I am designing and
simulation some antenna models with CST-MWS, and I need
also to use a SMA connector. Could you please send me
your SMA connector design files if you still have them?
I would appreciate. And I hope we can continue with
discussions related to antenna design and simulation
using CST or HFSS.

Best regards,

Hiromi
E-mail: hgoi@hotmail.com
 

Getting started with CST microwave studio.
 
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