WIRELESS ENERGY TRANSFER OVER VARIABLE DISTANCES BETWEEN RESONATORS OF SUBSTANTIALLY SIMILAR RESONANT FREQUENCIES

• US 20100133918A1
• Filed: 12/30/2009
• Published: 06/03/2010
• Est. Priority Date: 07/12/2005
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Karalis, Aristeidis, Soljacic, Marin, Joannopoulos, John D.
• Granted Patent: US 8,760,008 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02M 1/0064 Magnetic structures combining different functions, e.g. storage, filtering or transformation
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

Described herein are embodiments of a first resonator, with a resonant frequency f1, optionally coupled to an energy source; and a second resonator, with a resonant frequency f2, optionally coupled to an energy drain, located a variable distance from the first resonator. The first resonator and the second resonator may be coupled to provide near-field wireless energy transfer among the first resonator and the second resonator, and where f1 may be approximately equal to f2 and both f1 and f2 may be less than 400 MHz.

Claims

1. A system, comprising:

a first resonator, with a resonant frequency f1, optionally coupled to an energy source; and

a second resonator, with a resonant frequency f2, optionally coupled to an energy drain, located a variable distance from the first resonator;

wherein the first resonator and the second resonator are coupled to provide near-field wireless energy transfer among the first resonator and the second resonator;

and wherein f1 is approximately equal to f2 and both f1 and f2 are less than 400 MHz.

2. The system of claim 1, wherein the variable distance between the resonators is greater than 5 cm.

3. The system of claim 1, wherein the variable distance between the resonators is greater than 10 cm.

4. The system of claim 1, wherein the variable distance between the resonators is larger than the characteristic size of the smaller of the first resonator and the second resonator.

5. The system of claim 1, wherein each resonator comprises an electrical conductor shaped into one or more loops wound in substantially a single plane circumscribing a substantially planar area.

6. The system of claim 5, wherein the loops of the electrical conductors of each of the first and second resonators are in substantially the same plane.

7. The system of claim 5, wherein a line drawn from the center of the first resonator to the center of the second resonator is substantially normal to the circumscribed planar area of each resonator.

8. The system of claim 5, wherein a line drawn from the center of the first resonator to the center of the second resonator is substantially parallel to the circumscribed planar area of each resonator.

9. The system of claim 5, wherein a line drawn from the center of the first resonator to the center of the second resonator forms a different angle to the surface area circumscribed by the first resonator than to the circumscribed planar area of each resonator.

10. The system of claim 1, wherein at least one of the resonators has a quality factor, Q, greater than 100.

11. A method, comprising:

providing a first resonator, with a resonant frequency f1, optionally coupled to an energy source; and

providing a second resonator, with a resonant frequency f2, optionally coupled to an energy drain, located a variable distance from the first resonator;

wherein the first resonator and the second resonator are coupled to provide near-field wireless energy transfer among the first resonator and the second resonator;

and wherein f1 is approximately equal to f2 and both f1 and f2 are less than 400 MHz.

12. The method of claim 11, wherein the variable distance between the resonators is greater than 5 cm.

13. The method of claim 11, wherein the variable distance between the resonators is greater than 10 cm.

14. The method of claim 11, wherein the variable distance between the resonators is larger than the characteristic size of the smaller of the first resonator and the second resonator.

15. The method of claim 11, wherein each resonator comprises an electrical conductor shaped into one or more loops wound in substantially a single plane circumscribing a substantially planar area.

16. The method of claim 15, wherein the loops of the electrical conductors of each of the first and second resonators are in substantially the same plane.

17. The method of claim 15, wherein a line drawn from the center of the first resonator to the center of the second resonator is substantially normal to the circumscribed planar area of each resonator.

18. The method of claim 15, wherein a line drawn from the center of the first resonator to the center of the second resonator is substantially parallel to the circumscribed planar area of each resonator.

19. The method of claim 15, wherein a line drawn from the center of the first resonator to the center of the second resonator forms a different angle to the surface area circumscribed by the first resonator than to the circumscribed planar area of each resonator.

20. The method of claim 11, wherein at least one of the resonators has a quality factor, Q, greater than 100.