[geeks] Air filter material?

[Geoffrey S. Mendelson]

On Fri, Jan 12, 2007 at 12:20:48AM -0500, Sridhar Ayengar wrote:
> I doubt many mobile wifi setups pump out 4W.

It depends upon the beam width. If you take a 100mW signal from an 
omnidirectional antenna (a sphere) and reduce the beam width 40 times,
then it's over the limit. If you use one of the new "long range" 200mW
cards, then it's only 20 times. 

If you look at it in two dimensions, then you must cut the beam width from
360 degrees to 9 degrees. This would be a ring or donut, refered to
as a toriod. 

For three diminesions, since the pringles can is a circle, I'll assume that
again, it's 9 degrees from 360. That increases the radiated power another
40 times.   

There is some loss in the wire from the antenna to the transmitter,
but it's still enough.

Here it's even worse the limit, is 100mW. ANY gain must be subtracted
from the output power.

Geoff.

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