Wireless power transmitter with array of transmit coils

• US 10,110,070 B2
• Filed: 04/01/2016
• Issued: 10/23/2018
• Est. Priority Date: 04/01/2016
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yao, Zhen, Yang, Songnan, Elkhouly, Essam
• Primary Examiner(s): Houston, Adam
• Application Number:
  US15/089,113
• Publication Number:
  US 20170288460A1
• Time in Patent Office: 935 Days
• Field of Search: 307104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings

Abstract

Techniques for wireless transmitting power are described. An example power transmitting unit includes a magnetic resonance-type transmit coil array comprising a plurality of coil elements, wherein each coil element is tuned to a same resonant frequency. The power transmitting unit also includes a power generating circuitry to deliver current to the transmit coil array to wirelessly power a device within an active wireless charging area of at least one of the plurality of coil elements. Each coil element exhibits a plurality of zero point distances and the spacing between neighboring coil elements corresponds with the plurality of zero point distances.

Claims

1. A power transmitting unit, comprising:

a magnetic resonance-type transmit coil array comprising a plurality of coil elements, wherein each coil element is tuned to a same resonant frequency; and

a power generating circuitry to deliver current to the transmit coil array to wirelessly power a device within an active wireless charging area of at least one of the plurality of coil elements;

wherein each coil element comprises a plurality of zero point distances and the spacing between neighboring coil elements corresponds with the plurality of zero point distances.

2. The power transmitting unit of claim 1, wherein each coil element comprises a primary coil and a shield winding, wherein the primary coil comprises one or more windings.

3. The power transmitting unit of claim 2, wherein the shield winding comprises a conductive ring that concentrically surrounds the primary coil.

4. The power transmitting unit of claim 2, wherein the shield winding is conductively coupled to the primary coil and receives current from the power generating circuitry.

5. The power transmitting unit of claim 2, wherein the primary coil and the shield winding comprise a plurality of capacitors that separate the primary coil and the shield winding into a plurality of resonant segments.

6. The power transmitting unit of claim 2, wherein the primary coil comprises a plurality of primary windings that are driven by the power generating circuitry.

7. The power transmitting unit of claim 2, wherein the current in the primary coil is about 180 degrees out of phase with current in the shield winding.

8. The power transmitting unit of claim 1, wherein each coil element comprises at least three zero point distances.

9. The power transmitting unit of claim 1, wherein the plurality of coil elements are arranged in a hexagonal pattern, wherein a distance between any two coil elements of a hexagon is equal to one of the plurality of zero point distances.

10. The power transmitting unit of claim 1, wherein the plurality of coil elements are arranged in a rectangular pattern, wherein a distance between any two adjacent or overlapping coil elements is equal to one of the plurality of zero point distances.

11. A method of manufacturing a power transmitting unit, comprising:

forming a plurality of coil elements, wherein each coil element comprises a plurality of zero point distances;

disposing the plurality of coil elements in an overlapping pattern to form a magnetic resonance-type transmit coil array,

tuning each coil element to a same resonant frequency,

arranging the spacing between neighboring coil elements to correspond with the plurality of zero point distances; and

conductively coupling a power generating circuitry to the transmit coil array to wirelessly power a device within an active wireless charging area of at least one of the plurality of coil elements.

12. The method of claim 11, wherein forming each coil element comprises forming a primary coil and forming a shield winding around the primary coil.

13. The method of claim 12, wherein forming the shield winding comprises forming a conductive ring that concentrically surrounds the primary coil.

14. The method of claim 12, wherein forming each coil element comprises conductively coupling the shield winding to the primary coil.

15. The method of claim 12, wherein forming each coil element comprises separating the shield winding into a plurality of resonant segments coupled together by capacitors and separating the primary coil into a plurality of resonant segments coupled together by capacitors.

16. The method of claim 12, wherein forming the primary coil comprises forming a plurality of primary windings that are configured to be driven by the power generating circuitry.

17. The power transmitting unit of claim 12, wherein the current in the primary coil is about 180 degrees out of phase with current in the shield winding.

18. The method of claim 11, wherein each coil element comprises at least three zero point distances.

19. The method of claim 11, wherein disposing the plurality of coil elements in an overlapping pattern comprises arranging the plurality of coil elements in a hexagonal pattern, wherein a distance between any two coil elements of a hexagon is equal to one of the plurality of zero point distances.

20. The method of claim 11, wherein disposing the plurality of coil elements in an overlapping pattern comprises arranging the plurality of coil elements in a rectangular pattern, wherein a distance between any two adjacent or overlapping coil elements is equal to one of the plurality of zero point distances.

21. A transmit coil array to wirelessly transmit power to a receiving device, comprising:

a plurality of coil elements arranged in an overlapping pattern to form a magnetic resonance-type transmit coil array, wherein each coil element exhibits a plurality of zero point distances, and the spacing between neighboring coil elements corresponds with the plurality of zero point distances.

22. The transmit coil array of claim 21, wherein each coil element comprises a primary coil and a shield winding, wherein the primary coil comprises one or more windings.

23. The transmit coil array of claim 22, wherein the shield winding comprises a conductive ring that concentrically surrounds the primary coil.

24. The transmit coil array of claim 22, wherein the shield winding is conductively coupled to the primary coil and receives current from the power generating circuitry.

25. The transmit coil array of claim 22, wherein the primary coil and the shield winding comprise a plurality of capacitors that separate the primary coil and the shield winding into a plurality of resonant segments.