Every antenna has it's own natural frequency or more correctly
"wave-length"
The length (in meters) of the antenna is either tuned to a half or
quarter of the fundamental wave length
For 2.4 Ghz the fundamental wave length is 0.125 meters (125 mm) so
if want to design a simple half wave antenna (di-pole)
each element should be 62.5 mm in length. If you use a dish the focal
point of the parabolic antenna should be a multiple of this number
e.i. 62.5 or 125 or 187.5 or 250m. The antenna should be "T" shaped
with the top of the "T" being 62.5mm and the stork being
long enough to center it in at focal point. The top of the "T" should be
set horizontal.
All gain measurements are relative to a half wave omni directional
antenna (0db) as more complex antennas are
used the gain increases at the expense of all round directionality. For
point to point communications this can be minimized to 1-2%
so in theory (at least) the gain could be 180 to 360 times that of the
standard antenna.
The frequency of 2.4 Ghz is really only suitable for line of sight
(unabstructed by metal or conducting surfaces)
but you may get lucky with a reflection.
Good luck to all who search for the ultimate antenna
Henry
Duane wrote:
On Fri, 2006-08-04 at 11:44 -0400, Andrew Kohlsmith wrote:
Unfortunately having to account for wind, gravity and rifle barrel/muzzle
imperfections may STILL throw off your wireless aim. :-( At least you'll be
on the right track though.
Not to mention even good marksmen can't do more then a couple of km,
they'd be famous if they can do 8-10km :)
--
Henry L.Coleman [ VoIP-PBX ] Tel.1 866 415-5355 Ext.301
