Here is an interesting example of wearable antenna. It is directional,
alas...

http://www.wearable.ethz.ch/bluetexantenna.0.html

Here's how to modify this concept to make it "quasi-omnidirectional":

Make a dipole feed on the apex of the shoulder, drop one radiator down the
shoulder in front of, another - behind the body. Stitch it inside the suit.
For radiator, use one inch strips of material similar to one on the website
above, or any sort of fine conductive mesh. Match by adjusting lengths of
the radiators not to expected resonant length but to low SWR at your
required frequency. If the impedance will be too low - offset the feed
point.

Good luck.

Andrey

PS: say hi to Mr. Fractenna - he is playing his usual stunt, funny to watch.



"icelord" wrote in message
om...
Greetings,

I'm currently developing a project which requires a specialized
antenna. The system consists in a sensor equipped suit that delivers
the data to a server. I'm having problems findind a suitable antenna
for the suit, since it requires to be integrated on the suit or in a
backpack (whip antennas are out of the question, since the suit can't
have any holes). The main problem is the human body effect and the
size constraints. Gain is also a major requirement since the range of
the operations will be 400 meters with line of sight.
(Server side: 10 dBm Tx Power and a 6 dB whip antenna, Suit side: -96
dBm sensibility- freq:433 MHz)

I've tried a patch antenna (similar to the one provided by linx
technologies) but it didn't perform well. I've also tried a small whip
antenna but the ground plane dimensions aren't suitable for
integrating this type of antennas in the backpack. I've also found a
dipole body worn antenna ( http://www.panorama.co.uk )., but I'm not
sure of its performance. Currently I'm trying to develop my own
antenna, which consists of a pcb small loop antenna. I'm asking for
sugestions and maybe antenna references for this type of application.

Thanks in advance.