Planar structure and lumped components in Ansoft Designer

[ifelix]

Hi...
I've a problem in using Ansoft Designer.
I've a planar structure like a metallic patch feeded by a strip.
Now if I simulate this structure as a Planar EM model I note a capacitive behaviour as I expect. But now I would like to insert a lumped inductor component at the middle of the strip that feeds the patch to make it resonant.
Problem...how can I incorporate the lumped component in the planar structure and simulate it?
I can't create a Planar EM subcircuit and then connect the inductor to it because the inductor is planced inside the planar model and not on the outside of the box containing my structure...
How can I do?
The similar problem arises with loop antennas. When I need to make the loop resonant I've to insert a lumped capacitor on the pcb but then how I can simulate it...
I've tried to use HFSS with a rectangle with Lumped RLC boundary assigning to it L value but I've not obtained the results expected because I need to account for the parasitic effects of the lumped real components...It's for this reason I've thought to Designer but now I don't know how to resolve this problem...
Thanks in adv..

 

[Grig]

Re: Planar structure and lumped components in Ansoft Designe

Hi
You should use internal ports in em structure for lumped components
It is typical approach.

 

[ifelix]

Re: Planar structure and lumped components in Ansoft Designe

Excuse me...could you tell me how can I define internal ports in Ansoft Designer?

 

[Grig]

Re: Planar structure and lumped components in Ansoft Designe

Hi
Sorry! for I have used mom term: internal port
Use Gap Source in Ansoft!

 

[maxwellian]

Re: Planar structure and lumped components in Ansoft Designe

The only trouble is...how do you know how much discontinuity you have introduced into the problem using these gap ports? Does Designer de-embed these internal ports? That can be a big problem at higher frequencies.

 

[Grig]

Re: Planar structure and lumped components in Ansoft Designe

Hi
You can turn on or off deembeding
Chouse "use port solver" or not for this port