HFSS: Assign a voltage between two PEC sheets

[beetro78]

hfss pec

Hi everybody,

I get the following error from the HFSS simulator when I start my simulation:

"prova (E:/HFFS/New Projects/)
HFSSDesign1
[error] Adaptive solution setup, process abc3d : There are no tetrahedral faces assigned to boundary "PerfE1". Since boundary operations are order dependent, please check to make certain that this boundary is not being ignored because of other operations on the same surface. It is recommended that you redefine the boundary in question. (11:38 mag 17, 2007)
[error] Simulation completed with execution error on server: Local Machine. (11:38 mag 17, 2007)"

My simulation is essentially made up of two sheets, on which I assigned the PEC boundary condition and also a voltage source of 1V on a connecting line between them. I get the above error even if the HFSS validation tool shows that everything is OK.

To overcome the problem I tried to give a thickness to the sheets, but the simulation didn't work the same. Then I tried to substitute the PEC boundary assigning a PEC material to the thin sheets and I get the simulation run. But I need to simulate the ideal surfaces, and it sounds strange that I cannot work with surfaces in HFSS. So, does anyone know how to solve the problem?

Thank you in advance!

 

[jallem]

two pec

Post your file.

 

[beetro78]

what is pec hfss

I need to apply a voltage at the ends externalRing.

I select the two opposite faces of the externalRing and I try to define a voltage along a line connecting them, but HFSS says that the definition line is invalid.

Please help me.
Thank you!

 

[rfmw]

this file is not a proper PDF file! For hfss we exchange .hfss file. Is it from the older versions?

 

[beetro78]

Sorry, I updated the file.

Thks

 

[jallem]

But the model does not have any boundaries or
excitations?....Is this the same model you tried
to run?

 

[beetro78]

No. The simulation I run it's a bit different. I tried to run the same model with the ring made of PEC sheed (with 0 thickness), with a boudary condition of Radiation on the simulation volume and an excitation voltage at the ends of the externalRIng.

In the file I uploaded the model is the same, except for the finite thickness of the ring, but I cannot define the voltage: however I try to define the line voltage between the two opposite faces of the ExternalRing the SW says that the line is invalid.

So please, could you explain me step by step how to define this voltage?

Thanks.

 

[jallem]

I think I understand now. I once wanted to do
something similar. The port between two CURVED
lines. And this is the problem, sometimes the
software can't discriminate between points, I
solved using a square structure right at the point
where the port is.

 

[beetro78]

Actually I did not get your point. Anyway, I found the way to define the voltage between the ends of the externalRing: my mistake was to select the two opposite faces, instead I must select the upper or the lower face of the ring since the voltage has to be coplanar with the selected surface.

But, now i have another question: how can I analyze the impedance of the antenna defined, do I need to put a lumped port? If so, can someone explain me how to do that? Or which is the correct way to get the antenna impedance Vs frequency?

Thanks in advance!