How to calculate complex permittivity from complex conductivity

Click For Summary

Discussion Overview

The discussion revolves around the calculation of complex permittivity from complex conductivity data for metamaterials, specifically in the context of preparing data for electromagnetic simulation tools like CST and HFSS. Participants seek methods to derive real permittivity and frequency-dependent loss tangent from provided conductivity values across a frequency range.

Discussion Character

  • Technical explanation
  • Homework-related
  • Debate/contested

Main Points Raised

  • One participant presents a table of complex conductivity values at various frequencies and requests guidance on calculating complex permittivity.
  • Another participant suggests that conductivity and permittivity are orthogonal properties and recommends checking for existing permittivity tables for the material.
  • A different participant proposes a formula for calculating permittivity, indicating that the relationship might be expressed as ##\epsilon =\epsilon_0+\frac{i}{\omega} \sigma##.
  • Another participant shares a similar problem regarding the determination of complex permittivity from complex conductivity and seeks assistance.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and approaches to the problem, with no consensus reached on a specific method for calculating complex permittivity from complex conductivity.

Contextual Notes

There are indications of differing conventions in the field regarding the relationship between conductivity and permittivity, which may affect the calculations. The discussion does not resolve these conventions or the specific mathematical steps required.

Who May Find This Useful

Researchers and practitioners working with metamaterials, electromagnetic simulations, or those interested in the relationships between electrical properties of materials.

carbon9
Messages
46
Reaction score
0
Hi,

I got the complex conductivity vs. frequency table of a metamaterial. Its first lines are like this:

f conductivity
1GHz 0.004+0.00297i
1.1GHz 0.004+0.00295i
1.2GHz 0.003+0.00294i

the table goes up to 10GHz.

Now the problem is that I need to enter this material into electromagnetic simulation tools. But these tools require a real permittivity and frequency dependent loss tangent (CST and HFSS). So how can I calculate complex permittivity (real permittivity and loss tangent) from the above data?

Thanks in advance.
 
Physics news on Phys.org
I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
 
carbon9 said:
Hi,

I got the complex conductivity vs. frequency table of a metamaterial. Its first lines are like this:

f conductivity
1GHz 0.004+0.00297i
1.1GHz 0.004+0.00295i
1.2GHz 0.003+0.00294i

the table goes up to 10GHz.

Now the problem is that I need to enter this material into electromagnetic simulation tools. But these tools require a real permittivity and frequency dependent loss tangent (CST and HFSS). So how can I calculate complex permittivity (real permittivity and loss tangent) from the above data?

Thanks in advance.

I'm no expert in the field, but conductivity and permittivity would seem to be fairly orthogonal properties. Have you tried finding a table of permittivity for this material?

http://en.wikipedia.org/wiki/Electrical_conductivity

http://en.wikipedia.org/wiki/Permittivity

.
 
The problem is that there are many different conventions out there, but I would guess that in your case ##\epsilon =\epsilon_0+\frac{i}{\omega} \sigma##.
 
Hello,

I have the same problem. I have calculated the complex conductivity of a certain material at frequency fo. Now i want to introduce this material in HFSS. How can i determin the complex permitivity (real permitivity and loss tangent) from the complex conductivity?

If you figured out how to do this...can you please help me as well?

Many thanks in advance.
 

Similar threads

Graduate How is radio wave propagation modelled in seawater?
  • · Replies 12 ·
Replies
12
Views
11K