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Help: PML Scaling Factor and Implemantation In RF Module

Posted 15.08.2014, 16:18 GMT-4 RF & Microwave Engineering Version 4.4 1 Reply

Mohammad Parvinnezhad Hokmabadi
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Dear All,

Can somebody tell me what is PML scaling factor and curvature parameter in PML of RF 4.4?
I am going to sweep a large frequency range 4.8e14-8.8e14 in my simulation.
The structure is easy. Air and Substrate. both are semi-infinite.
I wanna use PML surrounding the structure and finally calculate reflection.
I attached the file.
I appreciate if you reply.
I discussed this problem with more detail also in
www.comsol.com/community/forums/general/thread/46787/
Please help.

Thanks,
Mohammad

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1 Reply Last Post 10.01.2016, 21:26 GMT-5
COMSOL Moderator

Hello Mohammad Parvinnezhad Hokmabadi

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Shreyank Gupta
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Posted: 9 years ago 10.01.2016, 21:26 GMT-5
Hello Mohammad Parvinnezhad Hokmabadi,

I did the simulation for PML behavior changing scaling and curvature parameter factor. I did this thing for acoustic in frequency domain. There are some points which I noticed to best describe PML:

1. PML material should be same as it's neighboring boundary and it's width should be typical greater than 5 wavelengths.
2. curvature parameter factor should never be negative
3. Scaling or absorption factor should be greater than 2/or smaller than -2 while curvature parameter factor should be greater than 3. If you keep both to 1 you will have reflections. Though I don't know the reason why curvature factor should be always positive. May be if you know you can tell me this thing.

Thanks and regards,
Shreyank Gupta
Hello Mohammad Parvinnezhad Hokmabadi, I did the simulation for PML behavior changing scaling and curvature parameter factor. I did this thing for acoustic in frequency domain. There are some points which I noticed to best describe PML: 1. PML material should be same as it's neighboring boundary and it's width should be typical greater than 5 wavelengths. 2. curvature parameter factor should never be negative 3. Scaling or absorption factor should be greater than 2/or smaller than -2 while curvature parameter factor should be greater than 3. If you keep both to 1 you will have reflections. Though I don't know the reason why curvature factor should be always positive. May be if you know you can tell me this thing. Thanks and regards, Shreyank Gupta

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