Wireless energy transfer with high-Q to more than one device
Described herein are embodiments of a source high-Q resonator, optionally coupled to an energy source, a second high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. A third high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. The source resonator and at least one of the second resonator and third resonator may be coupled to transfer electromagnetic energy from said source resonator to said at least one of the second resonator and third resonator.
1. A system, comprising:
a source resonator having a resonant frequency ω 1 , an intrinsic loss rate Γ 1 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 1 =ω 1 /(2Γ 1 ), the source resonator configured to be coupled to an energy source;
a second resonator having a resonant frequency ω 2 , an intrinsic loss rate Γ 2 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 2 =ω 2 /(2Γ 2 ), the second resonator located a distance from the source resonator; and
a third resonator having a resonant frequency ω 3 , an intrinsic loss rate Γ 2 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 3 =ω 3 /(2Γ 3 ), the third resonator located a distance from the source resonator,
wherein the source resonator and at least one of the second resonator and third resonator are configured to be coupled to wirelessly transfer electromagnetic energy from said source resonator to said at least one of the second resonator and third resonator when the source resonator is coupled to the energy source, and
wherein Q 1 >100 and Q 2 >100,
wherein the resonators are movable relative to one another and wherein the wireless energy transfer occurs over a range of distances, and
wherein κ/√{square root over (Γ 1 Γ 2 )}>0.2 over the range of distances, wherein κ is the wireless energy transfer rate.
2. The system of claim 1 , further comprising the energy source coupled to the source resonator.
3. The system of claim 1 , further comprising an energy drain configured to be coupled to the second resonator and an energy drain configured to be coupled to the third resonator.
4. The system of claim 3 , wherein at least one of the energy drains comprises a robot, vehicle, computer, cell phone, or a portable electronic device.
5. The system of claim 4 , wherein the at least one of the second resonator and third resonator is configured to provide useful power to the energy drain based on wirelessly transferred electromagnetic energy.
6. The system of claim 1 , wherein each intrinsic loss rate comprises a resistive component and a radiative component.
7. The system of claim 1 , wherein the source resonator is electromagnetically coupled to each of the second and third resonators.
8. The system of claim 7 , wherein the source resonator is configured to wirelessly transfer electromagnetic energy from the source resonator to each of the second and third resonators.
9. The system of claim 1 , wherein Q 3 >100.
10. The system of claim 1 , wherein at least one of the resonators is tunable.
11. The system of claim 1 , wherein the range of distances includes 5 cm.
12. The system of claim 1 , wherein the range of distances includes 10 cm.
13. The system of claim 1 , wherein the range of distances includes 30 cm.
14. The system of claim 1 , wherein κ/√{square root over (Γ 2 Γ 2 )}>0.5 over the range of distances.
15. The system of claim 1 , wherein κ/√{square root over (Γ 1 Γ 2 )}>1 over the range of distances.
16. The system of claim 1 , wherein the efficiency of the wireless energy transfer is at least 20% over the range of distances.
17. The system of claim 1 , wherein frequencies f 1 =ω 1 /2π, f 2 =ω 2 /2π, and f 3 =ω 3 /2π of the resonators are each at least 5 MHz.
18. The system of claim 1 , further comprising a feedback mechanism coupled to at least one of the resonators to correct for detuning to correct for detuning of the resonant frequencies.
19. The system of claim 1 , wherein the energy source is coupled to the source resonator, an energy drain is coupled to the second resonator, and the source resonator is electromagnetically coupled to the second resonator, and wherein the energy source and energy drain are configured to be driven to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ between the source resonator and the second resonator.
20. The system of claim 1 , wherein the source resonator is electromagnetically coupled to the second resonator, and wherein the source resonator and second resonator are configured to be adjustably tuned to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ between the source resonator and the second resonator.
21. The system of claim 1 , wherein the source resonator and the second resonator have different characteristic sizes.
22. The system of claim 1 , wherein f 1 =ω 1 /(2π), f 2 =ω 2 /(2π), and f 3 =ω 3 /(2π), and each of f 1 , f 2 , and f 3 is between about 5 MHz and 380 MHz.
23. A method, comprising:
providing a source resonator having a resonant frequency ω 1 , an intrinsic loss rate Γ 1 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 1 =ω 1 /(2Γ 1 ), the source resonator configured to be coupled to an energy source;
providing a second resonator having a resonant frequency ω 2 , an intrinsic loss rate Γ 2 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 2 =ω 2 /(2Γ 2 ), the second resonator located a distance from the source resonator; and
providing a third resonator having a resonant frequency ω 3 , an intrinsic loss rate Γ 3 , and capable of storing electromagnetic energy with a high intrinsic quality factor Q 3 =ω 3 /(2Γ 3 ), the third resonator located a distance from the source resonator,
wherein the source resonator and at least one of the second resonator and third resonator are configured to be coupled to wirelessly transfer electromagnetic energy from said source resonator to said at least one of the second resonator and third resonator when the source resonator is coupled to the energy source,
wherein Q 1 >100 and Q 2 >100,
wherein the resonators are movable relative to one another and wherein the wireless energy transfer occurs over a range of distances, and
wherein κ/√{square root over (Γ 1 Γ 2 )}>0.2 over the range of distances, wherein κ is the wireless energy transfer rate.
24. The method of claim 23 , wherein the source resonator and the second resonator have different characteristic sizes.
25. The method of claim 23 , wherein the source resonator is electromagnetically coupled to the second resonator, and wherein the source resonator and second resonator are adjustably tuned to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ between the source resonator and the second resonator.
26. The method of claim 23 , wherein the energy source is coupled to the source resonator.
27. The method of claim 23 , wherein an energy drain is coupled to the second resonator and an energy drain is coupled to the third resonator.
28. The method of claim 27 , wherein at least one of the energy drains comprises a robot, vehicle, computer, cell phone, or a portable electronic device.
29. The method of claim 27 , wherein the at least one of the second resonator and third resonator is configured to provide useful power to the energy drain based on wirelessly transferred electromagnetic energy.
30. The method of claim 23 , wherein each intrinsic loss rate comprises a resistive component and a radiative component.
31. The method of claim 23 , wherein the source resonator is electromagnetically coupled to each of the second and third resonators.
32. The method of claim 31 , wherein the source resonator is configured to wirelessly transfer electromagnetic energy from the source resonator to each of the second and third resonators.
33. The method of claim 23 , wherein Q 3 >100.
34. The method of claim 23 , wherein at least one of the resonators is tunable.
35. The method of claim 23 , wherein the range of distances includes 5 cm.
36. The method of claim 23 , wherein the range of distances includes 10 cm.
37. The method of claim 23 , wherein the range of distances includes 30 cm.
38. The method of claim 23 , wherein κ/√{square root over (Γ 1 Γ 2 )}>0.5 over the range of distances.
39. The method of claim 23 , wherein κ/√{square root over (Γ 1 Γ 2 )}>1 over the range of distances.
40. The method of claim 23 , wherein the efficiency of the wireless energy transfer is at least 20% over the range of distances.
41. The method of claim 23 , wherein frequencies f 1 =ω 1 /2π, f 2 =ω 2 /2π, and f 3 =ω 3 /2π of the resonators are each at least 5 MHz.
42. The method of claim 23 , wherein a feedback mechanism is coupled to at least one of the resonators to correct for detuning to correct for detuning of the resonant frequencies.
43. The method of claim 23 , wherein the energy source is coupled to the source resonator, an energy drain is coupled to the second resonator, and the source resonator is electromagnetically coupled to the second resonator, and wherein the energy source and energy drain is driven to increase the ratio of useful-to-lost power for varying wireless energy transfer rates κ between the source resonator and the second resonator.
44. The method of claim 23 , wherein f 1 =ω 1 /(2π), f 2 =ω 2 /(2π), and f 3 =ω 3 /(2π), and each of f 1 , f 2 , and f 3 is between about 5 MHz and 380 MHz.