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)
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.