Shielding a wireless signal

Archived from groups: alt.internet.wireless (More info?)

Hi,
I am interested in this topic mainly with regards to Bluetooth devices
but I presume it is equally relevant to wireless in general.

Can I shield my radio emitting device on one side, so that it only
emits in one direction? In other words, what materials could I put in
front of my router/bluetooth device to attenuate the signal?
Thanks,
Mike

Archived from groups: alt.internet.wireless (More info?)

On 7 Jan 2005 03:53:54 -0800, mikekelly100@hotmail.com wrote:

>I am interested in this topic mainly with regards to Bluetooth devices
>but I presume it is equally relevant to wireless in general.
>
>Can I shield my radio emitting device on one side, so that it only
>emits in one direction? In other words, what materials could I put in
>front of my router/bluetooth device to attenuate the signal?
>Thanks,
>Mike

It would be helpful if you would disclose what you're trying to
accomplish or what problem you're trying to solve.

You should distinguish between absorption and reflection. Both will
block a signal but in different ways. A piece of sheet metal, wire
mesh, or aluminium foil, will prevent the signal from going through,
but will also reflect the signal to who knows where. If you're trying
to control the distribution of the signal, this is not a great way to
do it.

Absorption converts the RF to heat. A piece of carbon doped
anti-static foam works nicely. A wet towel works well at 2.4GHz
because water absorbs RF. If you like spending money, Eccosorb:
http://www.eccosorb.com/catalog/eccosorb/anw.asp

For the true fanatics, we have frequency selective wallpaper:
http://www.newscientist.com/article.ns?id=dn6240


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558