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Where to enter dielectric loss
Posted 16.10.2015, 08:38 GMT-4 RF & Microwave Engineering Version 4.4, Version 5.0, Version 5.1 3 Replies
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Hi,
I am just confused, where should I enter the value of dielectric loss in the material properties?
I have seen some topics inte the forum, mentios that I can write it in the relative permittivity as real and imaginery part (For instance: 4-0.094i).
Furthermore,
I have also seen a topic which says I can write it in Electrical Conductivity area, doing with some calculations ( epsilon_c=epsilon-j*sigma/omega).
In the case of the following attachment, how should enter material properties?
Thanks a lot in advance.
I am just confused, where should I enter the value of dielectric loss in the material properties?
I have seen some topics inte the forum, mentios that I can write it in the relative permittivity as real and imaginery part (For instance: 4-0.094i).
Furthermore,
I have also seen a topic which says I can write it in Electrical Conductivity area, doing with some calculations ( epsilon_c=epsilon-j*sigma/omega).
In the case of the following attachment, how should enter material properties?
Thanks a lot in advance.
Attachments:
3 Replies Last Post 20.10.2015, 04:54 GMT-4
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Posted:
9 years ago
Osman,
Enter properties of dielectric material as following:
Relative permittivity: epsilonr=e'-j*e" or epsilonr=e'*(1-j*tan_delta)
Relative permeability: mur=1
Electrical conductivity: sigma=0
Expression epsilon_c=epsilon-j*sigma/omega is for complex-valued permittivity entering Maxwell wave equation solved in Comsol. It means that you can model conductor with zero conductivity and complex-valued permittivity - this approach is used to model metals at optical frequencies.
Regards,
Sergei
Enter properties of dielectric material as following:
Relative permittivity: epsilonr=e'-j*e" or epsilonr=e'*(1-j*tan_delta)
Relative permeability: mur=1
Electrical conductivity: sigma=0
Expression epsilon_c=epsilon-j*sigma/omega is for complex-valued permittivity entering Maxwell wave equation solved in Comsol. It means that you can model conductor with zero conductivity and complex-valued permittivity - this approach is used to model metals at optical frequencies.
Regards,
Sergei
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Posted:
9 years ago
Something else that you can do is to add another "wave equation, electric" domain feature in the emw interface. Make sure you select the specific domain you will use this for in your model. In that domain node, if you look down towards the middle or a bit lower, you will see pull down menus where you can specify materials. I don't have the program in front of me right now but there is a pull down menu that will allow you to select loss tangent, and a couple other choices. Once you select that, and your material references that domain as well, the material properties should update for needed items. I use this for custom materials as I can enter loss tangents easily.
There is more than one way to do this but just another way around it.
There is more than one way to do this but just another way around it.
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Posted:
9 years ago
Thank you so much for your help. Now It is clear.