TRANSMITTERS FOR WIRELESS POWER TRANSMISSION

• US 20100184371A1
• Filed: 09/16/2009
• Published: 07/22/2010
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hanspeter, Sieber, Lukas, Cook, Nigel P.
• Granted Patent: US 8,532,724 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H03F 3/2176 Class E amplifiers

Abstract

Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance. The transmitter further includes an amplifier configured to drive the transmit antenna and a matching circuit operably coupled between the transmit antenna and the amplifier. The transmitter also includes a capacitor integrating the antenna capacitance and a matching circuit capacitance.

Claims

1. A wireless power transmitter, comprising:

a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance;

an amplifier configured to drive the transmit antenna;

a matching circuit operably coupled between the transmit antenna and the amplifier; and

a capacitor integrating the antenna capacitance and a matching circuit capacitance.

2. The transmitter of claim 1, wherein the amplifier is configured as a class-E amplifier.

3. The transmitter of claim 2, wherein the class-E amplifier is configured as an asymmetric class-E amplifier.

4. The transmitter of claim 2, wherein the class-E amplifier is configured as a symmetric class-E amplifier.

5. The transmitter of claim 1, further comprising an inductor integrating an amplifier inductance and a matching circuit inductance.

6. The transmitter of claim 1, further comprising an intermediate driver configured to drive the amplifier.

7. The transmitter of claim 6, wherein the intermediate driver is configured as one of a resonant-type intermediate driver or a push-pull intermediate driver.

8. The transmitter of claim 1, wherein the matching circuit comprises a filtering circuit.

9. The transmitter of claim 1, wherein the transmit antenna comprises a pad antenna.

10. A wireless power transmitter, comprising:

a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance;

an amplifier configured as a dual half bridge amplifier to drive the transmit antenna; and

a capacitor integrating the antenna capacitance and junction capacitance of active switches in the amplifier.

11. A wireless power transmitter, comprising:

an amplifier, a transmit antenna, and a matching circuit operably coupled therebetween; and

a capacitor configured to include a capacitance of the antenna and a capacitance of the matching circuit.

12. The transmitter of claim 11, further comprising an inductor configured to include an inductance of the amplifier and an inductance of the matching circuit.

13. A method for transmitting wireless power, comprising:

driving a transmit antenna from an amplifier through a matching circuit; and

resonating the transmit antenna according to a transmit antenna capacitance realized in a capacitor shared with the matching circuit.

14. The method of claim 13, wherein the driving the transmit antenna comprises driving a transmit antenna from an amplifier through the matching circuit according to an amplifier inductance realized in an inductor shared with the matching circuit.

15. The method of claim 13, further comprising one of resonantly driving the amplifier or push-pull driving the amplifier.

16. The method of claim 13, wherein the amplifier is configured as a class-E amplifier.

17. A method for transmitting wireless power, comprising:

integrating a resonant capacitance of a transmit antenna into a capacitor including a capacitance of a matching circuit; and

driving the transmit antenna into resonance.

18. The method of claim 17, further comprising integrating an amplifier inductance into an inductor including an inductance of the matching circuit.

19. A wireless power transmitter, comprising:

means for driving a transmit antenna from an amplifier through a matching circuit; and

means for resonating the transmit antenna according to a transmit antenna capacitance realized in a capacitor shared with the matching circuit.

20. The transmitter of claim 19, wherein the means for driving the transmit antenna comprises means for driving a transmit antenna from an amplifier through the matching circuit according to an amplifier inductance realized in an inductor shared with the matching circuit.

21. A wireless power transmitter, comprising:

means for integrating a resonant capacitance of a transmit antenna into a capacitance of a matching circuit; and

means for driving the transmit antenna into resonance.

22. The transmitter of claim 21, further comprising means for integrating an amplifier inductance into an inductance of the matching circuit.

23. A wireless power receiver, comprising:

a receive antenna including a parallel resonator configured to resonate in response to a magnetic near-field and couple wireless power therefrom; and

a rectifier circuit coupled to the parallel resonator, the rectifier circuit configured as a multi-diode rectifier circuit including at least one diode selected based upon a parameter including at least one of peak repetitive revere voltage, average rectified forward current, maximum instantaneous forward voltage, and junction capacitance.

24. The receiver of claim 23, wherein the at least one diode exhibits a junction capacitance of about 50 pF and a maximum instantaneous forward voltage of about 380 mV at 1 ampere of current.

25. The receiver of claim 23, wherein the at least one diode comprises a double diode configured to reduce conduction losses.