WIRELESS ENERGY TRANSFER WITH REDUCED FIELDS

• US 20130200721A1
• Filed: 01/28/2013
• Published: 08/08/2013
• Est. Priority Date: 01/26/2012
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kurs, Andre B., Kesler, Morris P., Hall, Katherine L., Karalis, Aristeidis, Verghese, Simon, Efe, Volkan, Soljacic, Marin, Hijarrubia, Maria Empar Rollano, McCauley, Alexander P.
• Granted Patent: US 9,306,635 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H04B 5/24 Inductive coupling
• 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 90/14 Plug-in electric vehicles

Abstract

A magnetic resonator includes an inductor comprising a conductive first loop having a first dipole moment and a conductive second loop having a second dipole moment wherein a direction of the first dipole moment is substantially opposite to a direction of the second dipole moment and at least one capacitor in series with at least one of the first loop and the second loop.

Claims

1. A magnetic resonator comprising:

an inductor comprising a conductive first loop having a first dipole moment and a conductive second loop having a second dipole moment wherein a direction of the first dipole moment is substantially opposite to a direction of the second dipole moment; and

at least one capacitor in series with at least one of the first loop and the second loop.

2. The magnetic resonator of claim 1 wherein a quality factor of the resonator is greater than 100.

3. The magnetic resonator of claim 1 wherein the first loop and second loop are substantially the same size and have the same number of turns.

4. The magnetic resonator of claim 1 wherein a magnitude of the first dipole moment and a magnitude of the second dipole moment are substantially equal.

5. The magnetic resonator of claim 1 wherein the resonator is one component of a wireless power source.

6. The magnetic resonator of claim 1 wherein the resonator is one component of a wireless power device.

7. The magnetic resonator of claim 1 wherein the resonator is one component of a wireless power repeater.

8. The magnetic resonator of claim 1 wherein the first loop and the second loop are substantially co-planar.

9. The magnetic resonator of claim 1 wherein the first loop and the second loop of the resonator are oriented such that an axis of the first loop is substantially parallel to an axis of the second loop.

10. The magnetic resonator of claim 1 wherein the capacitor is a variable capacitor.

11. The magnetic resonator of claim 1 further comprising a second capacitor in parallel with the inductor.

12. A magnetic resonator comprising:

a plurality of conductive loops each having a dipole moment comprising a magnitude and a direction; and

a control system for adjusting the dipole moment of at least one of the plurality of loops to produce a predetermined far field radiation level.

13. The magnetic resonator of claim 12 wherein a sum of the dipole moments of each of the plurality of conductive loops is approximately zero.

14. A method comprising:

providing a plurality of conductive loops each having a dipole moment comprising a magnitude and a direction; and

selectively altering at least one dipole moment of at least one of the plurality of loops to produce a predetermined far field radiation level.

15. The method of claim 14 wherein selectively altering at least one dipole moment comprises:

measuring an existing far field radiation level;

determining a difference between the existing far field radiation level and the predetermined far field radiation level; and

selectively altering at least one dipole moment of at least one of the plurality of loops to effectively counteract the difference.

16. The method of claim 14 wherein the predetermined far field radiation level is approximately zero.

17. A wireless power source comprising:

at least one high-Q magnetic resonator for generating an oscillating magnetic field, and

at least one conducting plate positioned substantially perpendicular to the dipole moment of the resonator.

18. The wireless power source of claim 17 wherein the conductor plate is positioned to reduce the dipole radiation of the resonator in the far field of the resonator.

19. A wireless power device comprising:

at least one high-Q magnetic resonator for generating a current in the presence of an oscillating magnetic field, and

at least one conducting plate positioned substantially perpendicular to the dipole moment of the resonator.

20. The wireless power device of claim 19 wherein the conductor plate is positioned to reduce the dipole radiation of the resonator in the far field of the resonator.