Quote
Two identical helical copper coils, one for the
source and one for the load, were constructed by the
MIT team for magnetic coupling. By fine tuning the
height of the coils, they were able to cause strong
magnetic resonance coupling between the two coils at a
midrange distance. The source coil was in turn
inductively coupled to a single copper wire loop which is
attached to a Colpitts oscillator. A Colpitts oscillator is a
simple electronic oscillator that consists of two capacitors and one inductor to determine frequency [4].
The receiving magnetic coil was inductively coupled to a copper wire loop attached to a 60W light bulb.
heh, that's pretty old as far as principle goes, but good work MIT nonetheless.