Main Page | Report this Page
 
   
Science Forum Index  »  Physics - Electromagnetic Forum  »  Buliding the ultimate Faraday Cage
Page 1 of 1    
Author Message
Mac Lawson
Posted: Mon Oct 22, 2007 10:33 am
Guest
If I want to build the ultimate Faraday cage, into which no electromagneic
radiation can penertrate, what do I need?

Certain materials can block out certain frequencies, but even with these you
can combine wavelengths to produce the frequency within the faraday cage.

Is conductivity all that matters when creating such barriers? What about
other properties of materials, i.e., certain high frequency wavelengths can
penertrate steal, but not plastic? They seem to refelect off of low atomic
number materials.
Szczepan Białek
Posted: Mon Oct 22, 2007 1:51 pm
Guest
"Mac Lawson" <newthreat2000@yahoo.com> wrote
news:JeudnV2_LtA4X4HanZ2dnUVZ8qeknZ2d@saix.net...
Quote:

Is conductivity all that matters when creating such barriers? What about
other properties of materials,

The surface quality. Mirrors reflect some frequencies.
S*
Wimpie
Posted: Tue Oct 23, 2007 5:34 am
Guest
On 22 oct, 17:33, "Mac Lawson" <newthreat2...@yahoo.com> wrote:
Quote:
If I want to build the ultimate Faraday cage, into which no electromagneic
radiation can penertrate, what do I need?

Certain materials can block out certain frequencies, but even with these you
can combine wavelengths to produce the frequency within the faraday cage.

Is conductivity all that matters when creating such barriers? What about
other properties of materials, i.e., certain high frequency wavelengths can
penertrate steal, but not plastic? They seem to refelect off of low atomic
number materials.

High Mac,

About your faraday cage thought experiment. What about the frequency
range?

For very low frequency, only magnetic conductive materials will do the
job. In the HF to Light range, you can use materials with good
conductivity (metal). For the low part of the HF spectrum, the
thickness is of importance (skin effect).

Above light (for example X-rays and Gamma rays), the macroscopic
conductivity concept no longer holds and you have to dive into
microscopic atomic concepts.

Besides the attenuation for outside fields, because of temperature
above 0K, there will be always some EM radiation present in your cage
(especially at resonance frequencies).

About wavelengths. Just combining (addition) two different
frequencies, does not generate other frequencies, you need a non-
linear device for getting new frequencies.

Best regards,

Wim
PA3DJS
www.tetech.nl
 
Page 1 of 1       All times are GMT - 5 Hours
The time now is Fri Jul 25, 2008 5:33 pm