Faraday cage experiment - Static current

[kashmiro]

Hi everybody. Some expert advice needed here.

I am working into an experiment that consists of putting a wave emitter device (a wi-fi router for example) in a faraday cage so those waves don't spread outside the cage (or I get some attenuation at least). I have some questions:

- First of all, I would like to know if those emitted waves are reflected or absorbed by the Faraday cage.

- If those waves are absorbed as I think, they induce static current in the cage. If the wi-fi router is running for some days and this static current is not discharged properly, this would create any dangerous discharge when someone touching the cage?

- Is there any easy way to discharge the faraday cage? (Any other solution than plug it to the line)

I would be very grateful if you help me with these questions. I want to do the experiment in a correct and safe way :) Thank you very much.

 

[vanesch]

Hi everybody. Some expert advice needed here.

I am working into an experiment that consists of putting a wave emitter device (a wi-fi router for example) in a faraday cage so those waves don't spread outside the cage (or I get some attenuation at least). I have some questions:

- First of all, I would like to know if those emitted waves are reflected or absorbed by the Faraday cage.

Both, in fact. The Faraday cage will impose some boundary conditions which amount to some kind of reflection, but there will be currents induced in the metal, which will also lead to energetic losses and hence absorption. It will depend on the particular setup which is dominant.

- If those waves are absorbed as I think, they induce static current in the cage. If the wi-fi router is running for some days and this static current is not discharged properly, this would create any dangerous discharge when someone touching the cage?

No, not at all. There won't be any "static current", at most erratic currents, but there will not be any charge accumulation.

- Is there any easy way to discharge the faraday cage? (Any other solution than plug it to the line)

You can ground it (always a good idea, except for mobile applications), but your worry is not real in that what happens inside the cage won't "charge" it.