Paul Burridge wrote:
On Sat, 2 Aug 2003 18:24:44 -0500, "john graesser"
wrote:


Does it have to be a whip antenna? Why not try a horizontal circular loop?
Since you are working line of sight to the robot, the signal loss from going
from vertical to horizontal shouldn't matter much unless your transmitter is
extremely low power. A loop could be mounted inside a wooden or fiberglas
body and be pretty safe from attack.


If I believed this idea was workable I'd have implemented it by now.
You need to bear in mind that immediately beneath the polycarbonate
surface armor, there's a hulking great metal framework. Consequently,
sandwiching the antenna between the armour and the frame is going to
lead to unacceptable loss of radiated energy, I'd have thought. Unless
anyone knows differently..

Frequency limits prevent slot antennas in plate metal armor?

If so, loop antenna on top of the polycarb, with another
layer on top of that? You need a certain amount of standoff;
how much at your allowed frequencies? It'll amount to a box
or block of plastic stuck on the 'bot, but should be
relatively invulnerable.

Mark L. Fergerson