Receive antenna arrangement for wireless power

• US 8,581,542 B2
• Filed: 09/04/2009
• Issued: 11/12/2013
• Est. Priority Date: 09/08/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cook, Nigel P., Sieber, Lukas, Widmer, Hanspeter
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US12/554,478
• Publication Number:
  US 20100210233A1
• Time in Patent Office: 1,530 Days
• Field of Search: 320/107, 320/108, 320/109, 320/110, 320/111, 320/112, 320/113, 320/114, 320/115, 320/116, 455/269, 455/270, 455/271, 455/274, 336/84.R, 336/84.C, 336/84.M
• US Class Current: 320/108
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries

Abstract

Exemplary embodiments are directed to wireless charging. An electronic device may comprise at least one receive antenna integrated within an electronic device and configured to receive wireless power from a wireless transmit antenna. Further, the at least one receive antenna may be spaced from each conductive component within the electronic device having a clearance therebetween adapted to enable formation of a magnetic field around the loop conductor.

Claims

1. An electronic device comprising:

a housing;

a plurality of conductive elements positioned within the housing; and

a receive antenna configured to receive power wirelessly from a transmit antenna separated from the receive antenna, the receive antenna positioned within the housing so that a quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

2. The electronic device of claim 1, wherein the receive antenna comprises one of a single-loop conductor or a multi-loop conductor.

3. The electronic device of claim 1, further comprising a chargeable battery positioned within the housing, wherein the receive antenna is configured to be spaced from the chargeable battery.

4. The electronic device of claim 1, further comprising a non-conductive element positioned within the housing, wherein the receive antenna is positioned adjacent the non-conductive element.

5. The electronic device of claim 1, wherein a clearance is formed between the receive antenna and each conductive element, and wherein the clearance comprises a vacant space, one or more non-conductive elements, or any combination thereof.

6. The electronic device of claim 1, wherein the quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by more than a factor of about two as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

7. The electronic device of claim 1, wherein the quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by more than a factor of about two but by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

8. The electronic device of claim 1, wherein the receive antenna is spaced from each conductive element by at least about 1 to 2 millimeters.

27. The electronic device of claim 1, wherein the receive antenna is positioned within the housing such that a planar portion of the receive antenna is at least a distance away from each conductive element of the plurality of conductive elements.

9. A device, comprising:

a housing;

a plurality of conductive elements positioned within the housing; and

a receive antenna configured to receive power wirelessly from a transmit antenna separated by a first distance from the receive antenna, the receive antenna comprising a loop conductor positioned at least a second distance away from each conductive element of the plurality of conductive elements, the receive antenna configured to form an electromagnetic field around the loop conductor, the second distance of an extent so that a quality factor of the receive antenna measured after positioning the loop conductor at least the second distance away from each conductive element within the housing degrades by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

10. The device of claim 9, further comprising a non-conductive element, wherein the loop conductor is configured to be positioned proximate the non-conductive element.

11. The device of claim 10, wherein the electromagnetic field exists within the non-conductive element.

12. The device of claim 9, wherein the loop conductor is separated from each conductive element by at least a portion of a clearance therebetween.

13. A method of integrating a receive antenna within an electronic device, comprising:

positioning the receive antenna within a housing comprising a plurality of conductive elements so that a quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements; and

forming an electromagnetic field around a loop conductor of the receive antenna.

14. The method of claim 13, wherein forming the electromagnetic field around the loop conductor comprises forming a clearance between the loop conductor and each conductive element.

15. The method of claim 13, wherein the quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by more than a factor of about two as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

16. The method of claim 13, further comprising positioning a non-conductive element adjacent the loop conductor.

17. The method of claim 13, further comprising spacing the loop conductor from a chargeable battery by about 1 to 2 millimeters.

18. The method of claim 13, wherein forming the electromagnetic field around the loop conductor comprises forming the electromagnetic field entirely around the loop conductor.

19. A method of charging an electronic device, comprising:

separating a receive antenna from a transmit antenna;

receiving power in the receive antenna having a loop conductor separated from each conductive element of a plurality of conductive elements positioned within a housing thereby forming an electromagnetic field around the loop conductor, the receive antenna positioned within the housing so that a quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements; and

transferring power from the receive antenna to a chargeable battery coupled thereto.

20. The method of claim 19, wherein

the quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by more than a factor of about two as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

21. A device that facilitates charging an electronic device, the device comprising:

means for wirelessly receiving power, the wireless power receiving means separated from a transmit antenna and separated from each conductive element of a plurality of conductive elements positioned within a housing thereby forming an electromagnetic field around the wireless power receiving means, the wireless power receiving means positioned so that a quality factor of the wireless power receiving means measured after positioning the wireless power receiving means within the housing degrades by no more than a factor of about four as compared to the quality factor of the wireless power receiving means measured in the absence of the housing and the plurality of conductive elements; and

means for transferring power from the wireless power receiving means to a chargeable battery coupled thereto.

22. A system, comprising:

a plurality of conductive elements positioned within a housing; and

a receive antenna configured to wirelessly receive power from a transmit antenna separated from the receive antenna, the receive antenna positioned within the housing to form an electromagnetic field around a loop conductor of the receive antenna, the receive antenna positioned within the housing so that a quality factor of the receive antenna measured after positioning the receive antenna within the housing degrades by no more than a factor of about four as compared to the quality factor of the receive antenna measured in the absence of the housing and the plurality of conductive elements.

23. The system of claim 22, further comprising a non-conductive element positioned within the housing, wherein the loop conductor is positioned proximate the non-conductive element.

24. The system of claim 22, wherein the loop conductor is spaced about 1 to 2 millimeters from a conductive element closest thereto.

25. The system of claim 22, wherein the electromagnetic field is formed entirely around the loop conductor.

26. The system of claim 22, further comprising a receive circuitry connected to the receive antenna, the receive circuitry comprising an impedance match circuitry configured to match an impedance of the receive antenna to an impedance of the receive circuitry.