Patent ID: 8076801

Claim:
An apparatus for use in wireless energy transfer, the apparatus comprising: a first resonator structure configured for energy transfer with a second resonator structure, over a distance D larger than a characteristic size L 1 of said first resonator structure and larger than a characteristic size L 2 of said second resonator structure, wherein the energy transfer has a rate κ and is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure, wherein said resonant field of the first resonator structure has a resonance angular frequency ω 1 , a resonance frequency-width Γ 1 , and a resonance quality factor Q 1 =ω 1 /2Γ 1 at least larger than 100, and said resonant field of the second resonator structure has a resonance angular frequency ω 2 , a resonance frequency-width Γ 2 , and a resonance quality factor Q 2 =ω 2 /2Γ 2 at least larger than 100, wherein the absolute value of the difference of said angular frequencies ω 1 and ω 2 is smaller than the broader of said resonant widths Γ 1 and Γ 2 , and further comprising a power supply coupled to the first structure and configured to drive the first resonator structure or the second resonator structure at an angular frequency away from the resonance angular frequencies and shifted towards a frequency corresponding to an odd normal mode for the resonator structures to reduce radiation from the resonator structures by destructive far-field interference.