Building Materials Refractive Index?

[whitenight541]

Building Materials Refractive Index??

Hi all,

does anybody know the refractive indices of these materials (used in houses)?
- Wall bricks
- Wood (used in doors)
- Glass
- Plastic
- Concrete (in ceiling and floor)

and any other common materials :)

thanks in advance

 

[mgb_phys]

At what wavelength?
The refractive index of something that isn't transparent isn't much use

 

[whitenight541]

I want it to model transmission of electro-magnetic waves (not light) ..

at microwave frequency 2.4 GHz

If it is possible I want the absolute refractive index

thanks

 

[mgb_phys]

Google shows up a bunch of papers for microwave and Ka band frequency
In practice the wavelength is similair to the thickness of building materials in a wall so modelling it might be trickier - I would imagine it's also very dependent on water content of something like brick/concrete

 

[Bob S]

The index of refraction (= sqrt(dielectric constant)) in materials is a complex number, meaning that it has both refraction properties (like glass) and attenuation properties (like opaqueness). It is the attenuation property that reduces the transmission of microwaves.
Propagator = e^jωt-γz where γ is complex: γ = +/-sqrt(σμjω-εμω²)
The ratio of attenuation to dielectric constant is called the loss tangent.
tan(δ) = σ/εω. So attenuation is proportional to
e^{-sqrt(σμω)z}
See
http://en.wikipedia.org/wiki/Loss_tangent

α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω

 

[Andy Resnick]

I want it to model transmission of electro-magnetic waves (not light) ..

at microwave frequency 2.4 GHz

If it is possible I want the absolute refractive index

thanks

There's a lot of available data online and elsewhere, for example:

http://www.springerlink.com/content/xx771h5054762518/

 

[Bob S]

Here is another article on microwave losses in concrete and mortar. See Figures 6 thru 15.
http://web.mit.edu/istgroup/ist/documents/1998_EM%20properties%20of%20concrete%20at%20microwave%20freq%20range_HCR%20&%20OB.pdf
You might put some samples in a microwave oven. If the get warm (or hot), they are good absorbers. If they remain cool, they are not good absorbers.

 

[whitenight541]

There's a lot of available data online and elsewhere, for example:

http://www.springerlink.com/content/xx771h5054762518/

I don't have a springerlink account .. I would be so grateful if you just posted the refractive indices :)

Thanks in advance