Single-structure wireless charging receiver systems having multiple receiver coils

• US 10,491,041 B2
• Filed: 09/05/2018
• Issued: 11/26/2019
• Est. Priority Date: 09/06/2017
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wittenberg, Michael B., Brzezinski, Makiko K., Kowalski, Stefan A., Graham, Christopher S., McClure, Morgan T., de Jong, Erik G., Ness, Trevor J., Kardassakis, Peter J., Nath, Jayesh, Clavelle, Adam T., Ehman, Rex Tyler
• Primary Examiner(s): Williams, Arun C
• Application Number:
  US16/122,787
• Publication Number:
  US 20190074706A1
• Time in Patent Office: 447 Days
• Field of Search: 320108
• CPC Class Codes: H01F 27/2823 Wires H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/288 Shielding
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01Q 21/0093 Monolithic arrays
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Embodiments disclosed herein describe a wireless power receiving system for an electronic device includes: a first inductor coil configured to receive power primarily at a first frequency and from magnetic fields propagating in a first direction; and a second inductor coil configured to receive power primarily at a second frequency and from magnetic fields propagating in a second direction, wherein the first frequency is different than the second frequency.

Claims

1. A wireless charging receiver system, comprising:

a primary coil formed of a plurality of turns of stranded wire wound about a primary axis and configured to receive wireless power from time-varying magnetic fields generated at a first frequency and in a first direction;

a ferromagnetic shield disposed over at least two adjacent surfaces of the primary coil and over a portion of entire circumference of the at least two adjacent surfaces such that an annular segment of the primary coil is uncovered by the ferromagnetic shield; and

a secondary coil formed of a plurality of turns of stranded wire wound about a secondary axis disposed along a circumference centered around the primary axis, the secondary coil covers overlapping portions of the ferromagnetic shield and the primary coil and is configured to receive wireless power from time-varying magnetic fields generated at a second frequency different from the first frequency and in a second direction different from the first direction.

2. The wireless charging receiver system of claim 1;

wherein the ferromagnetic shield extends from a first radial location to a second radial location different from the first radial location.

3. The wireless charging receiver system of claim 2, wherein the secondary coil extends from a third radial location to a fourth radial location different from the third radial location.

4. The wireless charging receiver system of claim 1, wherein the at least two adjacent surfaces of the primary coil comprise an inner surface of the primary coil and a top surface of the primary coil.

5. The wireless charging receiver system of claim 1, wherein the secondary coil and the annular segment of the primary coil that is uncovered by the ferromagnetic shield are positioned in opposite halves of the wireless charging receiver system.

6. The wireless charging receiver system of claim 1, wherein the primary coil has a circular profile.

7. The wireless charging receiver system of claim 6, wherein the ferromagnetic shield comprises an inner edge and an outer edge, the inner edge includes two flat edges disposed in opposite halves of the ferromagnetic shield, and the outer edge has the circular profile.

8. The wireless charging receiver system of claim 1;

wherein the primary coil has an oblong profile comprising a first straight segment, a second straight segment, and two curved segments positioned between the first and second straight segments.

9. The wireless charging receiver system of claim 8, wherein the ferromagnetic shield comprises an inner edge and an outer edge, both of which include two flat edges disposed in opposite left and right halves of the ferromagnetic shield.

10. The wireless charging receiver system of claim 9, wherein the two flat edges of the outer edge of the ferromagnetic shield are coplanar with corresponding outer edges of the first and second straight segments of the primary coil.

11. A portable electronic device, comprising:

a housing comprising a top portion and a bottom portion configured to mate with the top portion to form an internal cavity; and

a wireless charging receiver system configured to receive power from time-varying magnetic fields propagating through the bottom portion of the housing, the wireless charging receiver system comprising;

a primary coil formed of a plurality of turns of stranded wire wound about a primary axis and configured to receive wireless power from time-varying magnetic fields generated at a first frequency and in a first direction;

a ferromagnetic shield disposed over at least two adjacent surfaces of the primary coil and over a portion of the entire circumference of the at least two adjacent surfaces such that an annular segment of the primary coil is uncovered by the ferromagnetic shield; and

a secondary coil formed of a plurality of turns of stranded wire wound about a secondary axis disposed along a circumference centered around the primary axis, the secondary coil covers overlapping portions of the ferromagnetic shield and the primary coil and is configured to receive wireless power from time-varying magnetic fields generated at a second frequency different from the first frequency and in a second direction different from the first direction.

12. The portable electronic device of claim 11, wherein the ferromagnetic shield extends from a first radial location to a second radial location different from the first radial location.

13. The portable electronic device of claim 12, wherein the secondary coil extends from a third radial location to a fourth radial location different from the third radial location.

14. The portable electronic device of claim 11, wherein the at least two adjacent surfaces of the primary coil comprise an inner surface of the primary coil and a top surface of the primary coil.

15. The portable electronic device of claim 11, wherein the secondary coil and the annular segment of the primary coil that is uncovered by the ferromagnetic shield are positioned in opposite halves of the wireless charging receiver system.

16. A wireless charging system, comprising:

a wireless charging transmitter comprising;

a housing having a charging surface; and

at least one transmitter coil formed of a plurality of turns of stranded wire disposed within the housing and below the charging surface, the at least one transmitter coil configured to generate time-varying magnetic fields through and above the charging surface; and

a wireless charging receiver comprising;

a primary coil formed of a plurality of turns of stranded wire wound about a primary axis and configured to receive wireless power from time-varying magnetic fields generated at a first frequency and in a first direction;

a ferromagnetic shield disposed over at least two adjacent surfaces of the primary coil and over a portion of the entire circumference of the at least two adjacent surfaces such that an annular segment of the primary coil is uncovered by the ferromagnetic shield; and

a secondary coil formed of a plurality of turns of stranded wire wound about a secondary axis disposed along a circumference centered around the primary axis, the secondary coil covers overlapping portions of the ferromagnetic shield and the primary coil and is configured to receive wireless power from time-varying magnetic fields generated at a second frequency different from the first frequency and in a second direction different from the first direction.

17. The wireless charging system of claim 16, wherein the ferromagnetic shield extends from a first radial location to a second radial location different from the first radial location.

18. The wireless charging system of claim 17, wherein the secondary coil extends from a third radial location to a fourth radial location different from the third radial location.

19. The wireless charging system of claim 16, wherein the at least two adjacent surfaces of the primary coil comprise an inner surface of the primary coil and a top surface of the primary coil.

20. The wireless charging system of claim 16, wherein the secondary coil and the annular segment of the primary coil that is uncovered by the ferromagnetic shield are positioned in opposite halves of the wireless charging receiver.