PML simulation error in HFSS

[Alex329]

Hi,

I would like to know if I use PML should it give the same gain results as when we use the radiation boundaries?
Also, when I apply the PML on all the surfaces of the airbox of my antenna, I get the following mistake after validation
%1 '%2':: The material of the PML base object cannot be anisotropic
I would like to know why do I get that mistake? Is it beacuse the antenna is anisotropic? Should I apply the PML on all the airbox faces? What is the proper way to assign the PML in that case ?

Thank you

 

[PlanarMetamaterials]

I would like to know if I use PML should it give the same gain results as when we use the radiation boundaries?

Approximately. PMLs are thought to be better, but they do have their own issues. I would sue a radiation boundary if possible.

I would like to know why do I get that mistake? Is it beacuse the antenna is anisotropic? Should I apply the PML on all the airbox faces? What is the proper way to assign the PML in that case?

It sounds like you have the wrong material assigned to your airbox. The material should be isotropic.

Good Luck!

 

[Alex329]

I want to use PML instead of radiation boundaries. What do you mean the material should be isotropic? How and where do you select an isotropic material boundary in hfss?

 

[PlanarMetamaterials]

The material settings should have a single entry for permittivity, permeability, conductivity, etc. -- none of these should be matrices.

There is no boundary, it's just the material settings. Air/vacuum is isotropic by default.

 

[Alex329]

The material settings should have a single entry for permittivity, permeability, conductivity, etc. -- none of these should be matrices.

There is no boundary, it's just the material settings. Air/vacuum is isotropic by default.

Thank you for you answer. I would like to know what do you mean by material settings? In my design i have feeding with vacuum and perfect conductor. I also have FR4 substrate and one airbox and virtual box with air material.
I didn't configure my objects as matrices. I don't even know how to check if they are matrices or not?
Do you mean by matrice, that I can't use PML with a rectangular substrate? (Sorry for my newb questions, but a your help would be appreciated)