HFSS - PML Guidelines Needed

[Catalyst]

hfss pml

Hello all,

I am having trouble simulating my antenna, not due to errors but because of the time it is taking to create the mesh. I had the simulation running last night for 6 hours and it didn't seem to get very far.

The model is basically this slow because I have a 10 metre by 10 metre airbox surrounding the antenna set as the radiation boundary. It is this big because I am working at around 13 MHz and I read in other posts that the boundaries should be at least 1/4 λ from the antenna. Is this correct?

I have also heard about using PMLs because it may mean a quicker solution but I am not sure hw to use PMLs

Can anyone tell me what I am doing wrong?

Can anyone explain how to use PML boundaires instead? do I still need such a large airbox?



Thanks


Cat

 

[sassyboy]

pml hfss

Catalyst

I want to stress that HFSS stands for High Frequency structure simulator. Therefore 13 MHz would not seem like a high frequency. And yes, a quarter-wavelength distance from the nearest radiating edge is required for the radiation boundary. PML would reduce your simulation time as the distance can reduce down to lamda/6 to lamda/10. In regards to setting up the PML, this is a regular query in this forum and so check out previous posts. Version 9 should be straight forward.

Alternatively, there are other simulation packages which employ the near-field boundary and the far-field is generated using Near-field to Far-field Transformation. This sort of boundary is very close to the radiating object and therefore very small total mesh in the overall simulation domain.

Sassyboy

 

[Catalyst]

pml+hfss

Thank you for the information

Do you recommend any other simulation packages that would be more suitable for the frequency I am working at?


Thanks


Cat

 

[sassyboy]

perfectly matched layers hfss

Try IMST Empire. The interface is very unix-looking and so may not to one's taste, but it does the job well. You could try CST Microwave Studio too, I find it very easy to use. Although Empire is much cheaper to own.

 

[Catalyst]

ansoft hfss pml

Does Microwave Studio definately support lower frequencies though? I can't find any info on it's frequency range.

 

[RFSimulator]

pml boundaries hfss

Hi,

as far as I know, HFSS uses by default "normal" absorbing boundary conditions (Mur?). PMLs are much better and you can get closer to your strcture if you use PMLs. MWS uses by default PMLs. How big is your antenna?


F.

 

[Catalyst]

hfss guidelines

about 60cm x 60cm loop antenna, It is an unbalanced setup.

It is fed by coaxial cable, The inner conductor is connected to the antenna as well as the outer conductor (ground).

This leads me to another question.........How do i set the outer conductor to ground?

 

[jjantenna]

hfss 13mhz simulation

I would like to use NEC (such as SuperNec) to simulate such a loop antenna.

 

[Catalyst]

site:www.edaboard.com pml radiation

Can anyone give any advice or is it not possible with HFSS?

 

[jjantenna]

hfss near field far field transformation

Attached is some slides from Ansoft regarding "Perfectly Matched Layers &
Linked Boundary Conditions".
Hope it helps a little.

 

[1987815]

hi cat have you already solve your problem? can you tell me how you did? thanks a lot