Wireless transfer of energy

1. The problem statement, all variables and given/known data
I have built a wireless system as described at the following site http://www.ar2r.50webs.com/wte/wte.html" [Broken]

I would like to be able to apply some theory to it and calculate a theoretical value for the transfer efficiency over certain distances

Does anybody have any idea of the theory I would need to use??



3. The attempt at a solution

In a paper by Andre Kurs, "Power transfer through strongly coupled resonances" he derives a formula for transfer efficiency from coupled mode theory however it is complicated and the coils he uses are self resonant, where as mine have a raised capacitive plate making them an LC resonant circuit

Any help would be greatly appreciated

Cheers