BIDIRECTIONAL WIRELESS POWER TRANSMISSION

• US 20100148723A1
• Filed: 09/01/2009
• Published: 06/17/2010
• Est. Priority Date: 09/02/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hanspeter, Sieber, Lukas, Cook, Nigel P.
• Granted Patent: US 8,947,041 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10207 parameter settings related to power consumption of the interrogator
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

Exemplary embodiments are directed to wireless power transfer. A wireless power transceiver and device comprise an antenna including a parallel resonator configured to resonate in response to a substantially unmodulated carrier frequency. The wireless power transceiver further comprises a bidirectional power conversion circuit coupled to the parallel resonator. The bidirectional power conversion circuit is reconfigurable to rectify an induced current received at the antenna into DC power and to induce resonance at the antenna in response to DC power.

Claims

1. A wireless power transceiver, comprising:

an antenna including a resonator configured to resonate in response to a substantially unmodulated carrier frequency; and

a bidirectional power conversion circuit coupled to the parallel resonator, the bidirectional power conversion circuit reconfigurable to rectify an induced current received at the antenna into DC power and to generate an induced current at a resonance frequency into the antenna from stored DC power.

2. The transceiver of claim 1, wherein the bidirectional power conversion circuit comprises a synchronous rectifier.

3. The transceiver of claim 2, wherein the synchronous rectifier includes at least two opposingly activated switches including shunt diodes thereacross to rectify received wireless power prior to activation of the switches.

4. The transceiver of claim 1, wherein the bidirectional power conversion circuit includes switching capacitance additive to capacitance in the parallel resonator.

5. The transceiver of claim 4, wherein a resonant frequency of the parallel resonator is determined at least in part on the switching capacitance.

6. The transceiver of claim 1, wherein the bidirectional power conversion circuit is configured to operate as a power source to the antenna and as a power sink from the antenna.

7. A device, comprising:

a battery for storing and donating power; and

a wireless power transceiver coupled to the battery and configured to store wirelessly received power in the battery received from a resonant magnetic near-field through a bidirectional power conversion circuit and to wirelessly transmit power from the battery through the bidirectional power conversion circuit to generate a resonant magnetic near-field.

8. The device of claim 7, wherein the bidirectional power conversion circuit comprises a synchronous rectifier.

9. The device of claim 8, wherein the synchronous rectifier includes at least one switch with switching capacitance associated therewith, the synchronous rectifier configured with the switching capacitance supplementing capacitance associated with an antenna configured to resonate in the magnetic near-field.

10. The device of claim 9, wherein a resonant frequency of the antenna is determined at least in part on the switching capacitance.

11. The device of claim 7, wherein the synchronous rectifier includes at least two opposingly activated switches including shunt diodes thereacross to rectify received wireless power prior to activation of the switches.

12. The device of claim 7, further comprising host device electronics configured to restrict donating excessive power from the battery.

13. A method for transceiving wireless power, comprising:

receiving an induced current from an antenna resonating in response to a magnetic near-field and rectifying the induced current into DC power through a bidirectional power conversion circuit when the bidirectional power conversion circuit is configured in receive mode; and

generating an induced current at a resonant frequency into the antenna from stored DC power through the bidirectional power conversion circuit and generating a magnetic near-field from the antenna when the bidirectional power conversion circuit is configured in transmit mode.

14. The method of claim 13, wherein the rectifying comprises actively switching the induced current into the DC power.

15. The method of claim 13, wherein the rectifying and the generating the induced current are synchronously timed based upon generated waveforms.

16. The method of claim 13, wherein generating the induced current further includes determining the resonant frequency based in part on additive switching capacitance in the bidirectional power conversion circuit.

17. The method of claim 13, further comprising restricting generating the magnetic near-field when the stored DC power is limited.

18. A wireless power transceiver, comprising:

means for receiving an induced current from an antenna resonating in response to a magnetic near-field and means for rectifying the induced current into DC power through a bidirectional power conversion circuit when the bidirectional power conversion circuit is configured in receive mode; and

means for generating an induced current at a resonant frequency into the antenna from stored DC power through the bidirectional power conversion circuit and means for generating a magnetic near-field from the antenna when the bidirectional power conversion circuit is configured in transmit mode.

19. The wireless power transceiver of claim 18, wherein the rectifying comprises actively switching the induced current into the DC power.

20. The wireless power transceiver of claim 18, wherein the rectifying and the generating the induced current are synchronously timed based upon generated waveforms.

21. The wireless power transceiver of claim 18, wherein generating the induced current further includes determining the resonant frequency based in part on additive switching capacitance in the bidirectional power conversion circuit.