Described herein are embodiments of a source resonator optionally coupled to an energy source, and a second resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. The source resonator and the second resonator may be coupled to provide κ/sqrt(Γ1Γ2)>0.2...http://www.google.de/patents/US20100127573?utm_source=gb-gplus-sharePatent US20100127573 - WIRELESS ENERGY TRANSFER OVER A DISTANCE AT HIGH EFFICIENCY
