WIRELESS POWER TRANSFER THROUGH A METAL OBJECT

• US 20160006293A1
• Filed: 02/06/2015
• Published: 01/07/2016
• Est. Priority Date: 07/07/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jeong, Seong Heon, Carobolante, Francesco, Chi, Mei-Li, Gong, Curtis, Fern, David George
• Granted Patent: US 10,381,875 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1656 Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• 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 50/12 of the resonant type
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A method and system for providing wireless power transfer through a metal object is provided. In one aspect, an apparatus for wirelessly receiving power via a magnetic field is provided. The apparatus includes a metal cover including an inner portion and an outer portion. The outer portion is configured to form a loop around the inner portion of the metal cover. The outer portion is configured to inductively couple power via the magnetic field. The apparatus includes a receive circuit electrically coupled to the outer portion and configured to receive a current from the outer portion generated in response to the magnetic field. The receive circuit is configured to charge or power a load based on the current.

Claims

1. An apparatus for wirelessly receiving power via a magnetic field, the apparatus comprising:

a metal cover comprising an inner portion and an outer portion, the outer portion configured to form a loop around the inner portion of the metal cover, the outer portion configured to inductively couple power via the magnetic field; and

a receive circuit electrically coupled to the outer portion and configured to receive a current from the outer portion generated in response to the magnetic field, the receive circuit configured to charge or power a load based on the current.

2. The apparatus of claim 1, further comprising a conductive coupler configured to electrically couple the outer portion to the inner portion.

3. The apparatus of claim 1, further comprising a conductive trace inserted within each of a plurality of slots separating the inner portion from the outer portion, the conductive trace configured to substantially form a second loop around the inner portion of the metal cover but within the outer portion of the metal cover.

4. The apparatus of claim 3, wherein the conductive trace within each of the plurality of slots is electrically coupled to the outer portion.

5. The apparatus of claim 4, wherein the outer portion forms a first turn of an inductor and the conductive trace forms a second turn of the inductor.

6. The apparatus of claim 1, wherein a plurality of slots separates the outer portion into a plurality of segments, the plurality of segments electrically coupled via at least one electrical coupler to form a single loop of a coil.

7. The apparatus of claim 6, wherein the at least one electrical coupler comprises an electrical filter.

8. The apparatus of claim 7, wherein the electrical filter is configured to allow the current to pass through the electrical coupler based on a frequency of the current.

9. The apparatus of claim 7, wherein the electrical filter is configured to allow the current to pass through the electrical coupler when the frequency of the current is substantially 6.78 MHz and is configured prevent the current from passing through the electrical coupler at frequencies substantially higher than 6.78 MHz.

10. The apparatus of claim 7, wherein the electrical filter comprises an inductive choke.

11. The apparatus of claim 1, wherein the apparatus further comprises a resonant circuit comprising the outer portion and a capacitor electrically coupled to the outer portion, the resonant circuit configured to resonate at the frequency of the magnetic field.

12. The apparatus of claim 1, wherein a plurality of slots separate the metal cover into the inner portion and the outer portion.

13. The apparatus of claim 12, wherein the plurality of slots extend substantially around a periphery of the metal cover.

14. The apparatus of claim 1, wherein the loop forms at least one turn of a coil.

15. The apparatus of claim 1, wherein the apparatus comprises at least one of a cellular phone, a GPS unit, a watch, a mobile media device, a laptop computer, or a key fob.

16. The apparatus of claim 1, further comprising a housing coupled to the metal cover.

17. The apparatus of claim 1, wherein the metal cover is configured as a metal back cover of a portable electronic device.

18. The apparatus of claim 1, wherein the outer portion comprises a metal ring comprising at least one slot, the at least one slot configured to make the metal ring discontinuous at least one location.

19. The apparatus of claim 1, wherein the inner portion functions as a reference ground to the outer portion.

20. The apparatus of claim 1, wherein a first resistance of the metal cover comprising the inner and outer portions in response to the magnetic field is reduced from a second resistance of a metal cover without inner and outer portions.

21. A method for wirelessly receiving power via a magnetic field, the method comprising:

wirelessly receiving power via a metal cover comprising an inner portion and an outer portion, the outer portion configured to form a loop around the inner portion of the metal cover, the outer portion configured to inductively couple power via the magnetic field; and

powering or charging a load based on the received power.

22. The method of claim 21, wherein wirelessly receiving power via the metal cover further comprises wirelessly receiving power via the metal cover further comprising a conductive trace inserted within each of a plurality of slots separating the inner portion from the outer portion, the conductive trace configured to substantially form a second loop around the inner portion of the metal cover but within the outer portion of the metal cover, the conductive trace electrically coupled to the outer portion.

23. The method of claim 21, wherein a plurality of slots separate the outer portion into a plurality of segments and wherein the plurality of segments are electrically coupled to each other via at least one electrical coupler to form a single loop antenna.

24. The method of claim 23, wherein the at least one electrical coupler comprises an electrical filter.

25. The method of claim 24, wherein the method further comprises selectively allowing current to pass through the electrical coupler based on a frequency of the current via the electrical filter.

26. The method of claim 25 wherein selectively allowing current to pass through the electrical coupler based on the frequency comprises allowing the current to pass through the electrical coupler when the frequency of the current is substantially 6.78 MHz and preventing the current from passing through the electrical coupler at frequencies substantially higher than 6.78 MHz.

27. The method of claim 21, wherein the metal cover is part of at least one of a cellular phone, a GPS unit, a watch, a mobile media device, a laptop computer, or a key fob.

28. The method of claim 21, wherein a housing is coupled to the metal cover.

29. The method of claim 21, wherein a plurality of slots separate the metal cover into the inner portion and the outer portion.

30. The method of claim 21, wherein the inner portion functions as a reference ground to the outer portion.

31. The method of claim 21, wherein a first resistance of the metal cover comprising the inner and outer portions in response to the magnetic field is reduced from a resistance of a metal cover without inner and outer portions.

32. An apparatus for receiving wireless power from a magnetic field, comprising:

conducting means for partially housing a portable electronic device, the conducting means comprising an inner portion and an outer portion, the outer portion configured to form a loop around the inner portion of the conducting means, the outer portion comprising means for inductively coupling power via the magnetic field; and

means for powering or charging a load based on power receiving via the outer portion.

33. An apparatus for wirelessly receiving power, the apparatus comprising:

a housing portion configured to form a back of a portable electronic device, the housing portion having a first dimension, the housing portion comprising;

a metal portion having a second dimension the same size as or having a size that covers a majority of the first dimension of the housing portion, at least a portion of the metal portion configured to inductively couple power via a magnetic field at a level sufficient for charging or powering a load of the portable electronic device; and

an electrical connection electrically coupled to the metal portion and configured to provide received power to the portable electronic device.

34. The apparatus of claim 33, wherein the metal portion is configured to generate current in response to a voltage induced by the magnetic field generated by a transmitter.

35. The apparatus of claim 33, wherein the metal portion comprises an inner portion and an outer portion, the outer portion configured to form a loop around the inner portion of the metal portion forming at least one turn of a coil configured to inductively couple the power via the magnetic field.