APPARATUS AND METHODS FOR WIRELESS POWER TRANSMITTER COIL CONFIGURATION

• US 20170012475A1
• Filed: 04/08/2016
• Published: 01/12/2017
• Est. Priority Date: 07/09/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Zhang, Zhe, Nadakuduti, Jagadish, Lu, Lin, Guckian, Paul
• Granted Patent: US 10,511,191 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

Methods and apparatus are disclosed for wirelessly transmitting power. In one aspect, an apparatus for wireless transmitting power is provided. The apparatus comprises a first coil loop defining a first area, the first coil loop conducting current at a first current value for generating a first magnetic field. The apparatus further comprises a second coil loop surrounding the first coil loop and defining a second area, the second coil loop conducting current at a second current value generating a second magnetic field, wherein a ratio of the first current value to the first area is substantially equal to a ratio of the second current value to the second area.

Claims

1. An apparatus for wirelessly transmitting power, the apparatus comprising:

a first coil loop defining a first area, the first coil loop conducting current having a first current value and generating a first magnetic field; and

a second coil loop surrounding the first coil loop and defining a second area, the second coil loop conducting current having a second current value and generating a second magnetic field, wherein a ratio of the first current value to the first area is substantially equal to a ratio of the second current value to the second area.

2. The apparatus of claim 1, wherein the second area is larger than the first area and the second current value is greater than the first current value.

3. The apparatus of claim 1, wherein the second coil loop comprises two or more turns, and wherein a ratio of a number of turns of the first coil loop to the first area is substantially equal to a ratio of the two or more turns of the second coil loop to the second area.

4. The apparatus of claim 3, wherein the first coil loop and the second coil loop comprise a single winding of a conductive material coupled to a current source.

5. The apparatus of claim 1, wherein the first coil loop comprises one or more turns and the second coil loop comprises two or more turns, and wherein each turn in the second coil loop is conducting current having a current value substantially equal to a current value in each turn in the first coil loop.

6. The apparatus of claim 1, wherein the second coil loop comprises two or more turns, and wherein a ratio of a number of turns of the first coil loop to the first current value is substantially equal to a ratio of the two or more turns of the second coil loop to the second current value.

7. The apparatus of claim 1, wherein the first coil loop is coupled to a first current source and the second coil loop is coupled to a second current source.

8. The apparatus of claim 1, wherein the first coil loop and the second coil loop are coupled to a common current source.

9. The apparatus of claim 1, wherein a ratio of the first current value to the second current value is substantially equal to a ratio of a number of turns in the first coil loop to a number of turns in the second coil loop.

10. A method of transmitting wireless power, comprising:

generating a first magnetic field via a first coil loop, the first coil loop defining a first area and conducting current at a first current value; and

generating a second magnetic field via a second coil loop, the second coil loop surrounding the first coil loop and defining a second area, the second coil loop conducting current at a second current value, wherein a ratio of the first current value to the first area is substantially equal to a ratio of the second current value to the second area.

11. The method of claim 10, wherein the second area is larger than the first area and the second current value is greater than the first current value.

12. The method of claim 10, wherein the second coil loop comprises two or more turns, and wherein a ratio of a number of turns of the first coil loop to the first area is substantially equal to a ratio of the two or more turns of the second coil loop to the second area.

13. The method of claim 12, wherein the first coil loop and the second coil loop comprise a single winding of a conductive material coupled to a current source.

14. The method of claim 10, wherein the first coil loop comprises one or more turns and the second coil loop comprises two or more turns, and wherein each turn in the second coil loop is conducting current having a current value substantially equal to a current value in each turn in the first coil loop.

15. The method of claim 10, wherein the second coil loop comprises two or more turns, and wherein a ratio of a number of turns of the first coil loop to the first current value is substantially equal to a ratio of the two or more turns of the second coil loop to the second current value.

16. The method of claim 10, further comprising driving the first coil loop with the first current value from a first current source and driving the second coil loop with the second current value from a second current source.

17. The method of claim 10, further comprising driving the first coil loop and the second coil loop with the first and second current values from a common current source.

18. The method of claim 10, wherein a ratio of the first current value to the second current value is substantially equal to a ratio of a number of turns in the first coil loop to a number of turns in the second coil loop.

19. An apparatus for wirelessly transmitting power, the apparatus comprising:

a first means for generating a first magnetic field wound about a point to define a first area, the first means for generating the first magnetic field conducting time-varying electrical current at a first current value;

a second means for generating a second magnetic wound about the point to define a second area, the second means for conducting electrical current conducting time-varying electrical current at a second current value, wherein a ratio of the first current value to the first area is substantially equal to a ratio of the second current value to the second area.

20. The apparatus of claim 19, wherein the second area is larger than the first area and the second current value is greater than the first current value.

21. The apparatus of claim 19, wherein the second means comprises two or more turns, and wherein a ratio of a number of turns of the first means to the first area is substantially equal to a ratio of the two or more turns of the second means to the second area.

22. The apparatus of claim 21, wherein the first means and the second means comprise a single winding of a conductive material coupled to a current source.

23. The apparatus of claim 19, wherein the first means comprises one or more turns and the second means comprises two or more turns, and wherein each turn in the second means is conducting current having a current value substantially equal to a current value in each turn in the first means.

24. The apparatus of claim 19, wherein the second means comprises two or more turns, and wherein a ratio of a number of turns of the first means to the first current value is substantially equal to a ratio of the two or more turns of the second means to the second current value.

25. The apparatus of claim 19, wherein the first means is coupled to a first current source and the second means is coupled to a second current source.

26. The apparatus of claim 19, wherein the first means and the second means are coupled to a common current source.

27. The apparatus of claim 19, wherein a ratio of the first current value to the second current value is substantially equal to a ratio of a number of turns in the first means to a number of turns in the second means.

29. The apparatus of claim 27, wherein the at least one driver circuit comprises:

a first driver circuit configured to drive the first coil loop with the first current value; and

a second driver circuit configured to drive the second coil loop with the second current value.

30. The apparatus of claim 27, wherein the second coil loop comprises two or more turns of a conductive material.

28. An apparatus for wirelessly transmitting power, the apparatus comprising:

a first coil loop defining a first area, the first coil loop conducting current having a first current value and generating a first magnetic field; and

a second coil loop separated from the first coil loop and defining a second area, the second coil loop conducting current having a second current value and generating a second magnetic field; and

at least one driver circuit configured to drive the first coil with a first current value and the second coil loop with a second current value, the first current value different from the second current value, wherein a ratio of the first current value to the first area is substantially equal to a ratio of the second current value to the second area.