Wireless energy transfer

Abstract

Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy non-radiatively with a second resonator structure over a distance greater than a characteristic size of the second resonator structure. The non-radiative energy transfer is mediated by a coupling of a resonant field evanescent tail of the first resonator structure and a resonant field evanescent tail of the second resonator structure.

1 . An electromagnetic resonance non-contact power transmission device comprising:
 a transmitter including a transmitter high-Q resonance element having a mechanism for varying a resonant frequency,   a transmitter excitation element coupled to the transmitter resonance element by electromagnetic induction, and an alternating current source for applying an alternating current at the same frequency as the resonant frequency to the transmitter excitation element; and   a plurality of receivers each including a receiver high-Q resonance element having a specific resonant frequency, a receiver excitation element coupled to the receiver resonance element by electromagnetic induction, and an output circuit for outputting an electric current induced by the receiver excitation element,   wherein electric power is transmitted from the transmitter to any of the plurality of receivers.   
     
     
         2 . The electromagnetic resonance non-contact power transmission device of  claim 1 , wherein the transmitter resonance element is formed of an air-core coil, and the transmitter includes an adjusting unit for adjusting a geometric property of the air-core coil. 
     
     
         3 . The electromagnetic resonance non-contact power transmission device of  claim 2 , wherein the transmitter includes a monitor and a feedback circuit for controlling the adjusting unit. 
     
     
         4 . The electromagnetic resonance non-contact power transmission device of  claim 3 , wherein the receiver resonance element is formed of an air-core coil, and power transmission to each of the receivers is controlled by information exchange between the resonant objects. 
     
     
         5 . The electromagnetic resonance non-contact power transmission device of  claim 1 , wherein the transmitter resonance element is formed of an air-core coil, and the transmitter has an adjusting unit for adjusting a geometric property of the air-core coil.