Learning Forum

[bamdadslr]

Hi,

 

I am trying to simulate an overhead transmission line (6 conductor) in HFSS located on a PEC ground. I dont want to have reflections from the end of transmission line in a specific time range when I get IFFT, so I need to terminate the conductors with matching impedances (considering very long conductors is another alternative, but needs to many mesh, so not feasible).Is there any was to define matching terminations? Is using circuit ports an option? other way is to assign radiation boundary to a sheet where the conductors end, but not sure hoe effective it is in removing the reflections.

 

Thanks.

[Sorceress Gia]

Add a 2nd lumped port to the end of your transmission line and set the port impedance to the desired termination impedance.

[bamdadslr]

Thank you so much for your quick answer. There are two challenges in doing so. First, considering that its a double circuit overhead transmission line with 2 shield wires (there are self and mutual impedance), I have to define port between each and every two of these 8 conductors. For defining the mutual impedance between the phases of the two circuit (of the double circuit line), their distance is around 18 m, which is not negligible for defining a port (simulation frequency 1k-10MHz). Second, the other edge of the port (for self impedance of each wire) should be vertically connected to the ground?

 

Thanks.

[Sorceress Gia]

If your model results in an odd termination then you should draw the additional realistic geometric features to properly model the termination...