# Carbon fiber's EM parameters

#### Unconscious

I would like to know parameters of this material, such as: $\epsilon$, $\mu$ and $\sigma$, for EM simulations with CST.
I can't find anything similar to carbon fibers or general plastic in the CST material library. Google is not helping me this time.
Does anyone know something more on this topic?

Thanks.

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#### Baluncore

Carbon fibres come in many forms. How is the surface fabricated? What holds it together?

Carbon fibres are long thin resistors. They are not effected by magnets, so ur = 1.00 and I expect Er will also be 1.00 because they are a very small component of the space they fill, but conductivity will be most important. Cross connections between fibres will be determined by the binder that holds them in place. We need more information about your application before we can help further.
Here is a start.

#### Unconscious

From the linked PDF I see that the value of $\sigma$ can oscillate between 526 S/cm and 2200 S/cm.

How is the surface fabricated? What holds it together?
Unfortunately, I don't know. I simply would simulate the RCS of a drone propeller, "made of carbon fiber".

#### Baluncore

There are many google hits for; RCS of composite propeller
Maybe search for stealth specifications of composites.

If you want to design a propeller that will not return a significant doppler signature, then you will have to select composites designed to have a surface resistance of 377 ohm, like air. A duct around the prop will also need to be absorptive so the shadow of the prop is not seen. You must select materials based on predictable EM properties.

If you are modeling an existing propeller, you will have to measure it.
Have you been following things like this;

#### Unconscious

Thanks for the documents.

"Carbon fiber's EM parameters"

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