Wireless energy transfer using planar capacitively loaded conducting loop resonators
View Patent ↗Described herein are improved capabilities for a source resonator having a Q-factor Q 1 >100 and a characteristic size x 1 coupled to an energy source, and a second resonator having a Q-factor Q 2 >100 and a characteristic size x 2 coupled to an energy drain located a distance D from the source resonator, where the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator.
1. A wireless power transfer system comprising:
a source unit with at least one source planar magnetic resonator coupled to a power generator, and arranged such that the dipole moment of the said source planar magnetic resonator is oriented substantially in a plane of the source planar magnetic resonator;
at least one device unit with at least one device planar magnetic resonator arranged such that the dipole moment of the said device planar magnetic resonator is oriented substantially in a plane of the device planar magnetic resonator; and
an active area around the source unit such that when the said device unit is placed in the active area alternating magnetic fields generated by at least one of the source planar magnetic resonators induce a current in at least one of the said device planar magnetic resonators of the said device unit,
wherein the said active area of the power transfer system is at least two times the area enclosed by the perimeter of the said source planar magnetic resonator.
2. The system of claim 1 , wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 1%.
3. The system of claim 1 , wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 10%.
4. The system of claim 1 , wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 50%.
5. The system of claim 1 , wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 10 mW of power to the device unit.
6. The system of claim 1 , wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 5W of power to the device unit.
7. The system of claim 1 , wherein the active area is the area in which the induced current in at least one device planar magnetic resonator of the device unit is sufficient to deliver at least 1 kW of power to the device unit.
8. The system of claim 1 , wherein the active area is at least five times the area enclosed by the perimeter of the said source planar magnetic resonator.
9. The system of claim 1 , wherein at least one source planar magnetic resonator comprises at least one electrical conductor wrapped around a core of magnetic material.
10. The system of claim 1 , wherein at least one device planar magnetic resonator comprises at least one electrical conductor wrapped around a core of magnetic material.
11. The system of claim 1 , wherein at least one planar magnetic resonator of the said system comprises at least one electrical conductor wrapped around a core of magnetic material.
12. The system of claim 11 , further comprising at least one electrical component network, wherein the said electrical component network is coupled to at least one electrical conductor.
13. The system of claim 12 , wherein at least one electrical component network comprises at least one capacitor.
14. The system of claim 12 , wherein at least one electrical component network comprises at least one inductor.
15. The system of claim 12 , wherein at least one electrical component network comprises at least one variable component.
16. The system of claim 12 , wherein at least one electrical component network comprises at least one tunable component.
17. The system of claim 12 , wherein the electrical component network is connected to the at least one electrical conductor using a direct physical connection.
18. The system of claim 12 , wherein the electrical component network is connected to the at least one electrical conductor using an inductive connection.
19. The system of claim 11 , wherein the electrical conductor is wrapped around the core of magnetic material forming loops of which some are not coaxial.
20. The system of claim 11 , wherein at least one planar magnetic resonator has a quality factor Q>100.
21. The system of claim 11 , wherein all the planar magnetic resonators of the system have a quality factor greater than 100.
22. The system of claim 11 , wherein the core comprises ferrite materials.
23. The system of claim 11 , wherein the core contains shielded enclosures.
24. The system of claim 11 , wherein the core contains shielded enclosures at least partially encased in magnetic materials.
25. The system of claim 11 , wherein the smallest dimension of the core is at most 30% of the largest dimension.
26. The system of claim 11 , wherein the electrical conductor comprises litz wire.
27. The system of claim 11 , wherein the electrical conductor comprises a flex circuit.
28. The system of claim 11 , wherein the electrical conductor comprises printed conductor traces.
29. The system of claim 11 , wherein the electrical conductor is wrapped around the said core to generate said active area that is substantially uniform around the resonator.
30. The system of claim 11 , wherein the electrical conductor is wrapped around the said core to generate said active area that is substantially non uniform around the resonator.
31. The system of claim 11 , further comprising a capacitively loaded conductor loop resonator in the source unit wherein the capacitively loaded conductor loop is coupled to a power generator and is shaped as to form loops that are in the plane of at least one of the source planar magnetic resonators.
32. The system of claim 31 , further comprising a capacitively loaded conductor loop resonator in the device unit wherein the capacitively loaded conductor is shaped as to form loops that are in the plane of at least one of the device planar magnetic resonators.
33. The system of claim 11 , further comprising a capacitively loaded conductor loop resonator shaped as to form loops that are in the plane of the source planar magnetic resonator.
34. The system of claim 11 , wherein the core is shaped to generate said active area that is substantially uniform around the source planar magnetic resonator.
35. The system of claim 11 , wherein the core is shaped to generate said active area that is substantially non uniform around the source unit.
36. The system of claim 1 , wherein at least one source planar magnetic resonator comprises two conductors wrapped around orthogonal axes of a core of magnetic material.
37. The system of claim 1 , wherein at least one device planar magnetic resonator comprises two conductors wrapped around orthogonal axes of a core of magnetic material.
38. The system of claim 11 , wherein the source unit is integrated with an electronic device.
39. The system of claim 11 , wherein the source unit is designed to be placed on a flat surface.
40. The system of claim 11 , wherein the source unit is designed to be hung from a wall or a mount.
41. A wireless power transfer method comprising the steps of:
providing a source unit with at least one source planar magnetic resonator coupled to a power generator and arranged such that the dipole moment of the said source planar magnetic resonator is oriented substantially in a plane of the source planar magnetic resonator,
providing at least one device unit with at least one device planar magnetic resonator and arranged such that the dipole moment of the said device planar magnetic resonator is oriented substantially in the plane of the device planar magnetic resonator, and
providing power to at least one of the said source planar magnetic resonators through the power generator to generate an active area of alternating electromagnetic field around the source unit,
wherein the said active area is at least two times the area enclosed by the perimeter of the said source planar magnetic resonator.
42. The method of claim 41 , wherein the active area is the area in which the power transfer efficiency between the source unit and the device unit exceeds 1%.
43. The method of claim 41 , wherein the active area is at least five times the area enclosed by the perimeter of the said source planar magnetic resonator.
44. The method of claim 41 , wherein at least one planar magnetic resonator of the said method comprises at least one electrical conductor wrapped around a core of magnetic material.
45. The method of claim 41 , wherein at least one planar magnetic resonator has a quality factor greater than 100.
46. The method of claim 41 , wherein all the planar magnetic resonators of the method have a quality factor greater than 100.