TRANSMITTERS FOR WIRELESS POWER TRANSMISSION

• US 20140001882A1
• Filed: 09/06/2013
• Published: 01/02/2014
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: COOK, Nigel P., SIEBER, Lukas, WIDMER, Hanspeter
• Granted Patent: US 9,425,653 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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 circuit configured as a resonant tank comprising a first capacitor coupled with a first inductor, the transmit circuit configured to wirelessly transmit power in response to a time-varying signal; and

a driver circuit operably coupled to the transmit circuit, the driver circuit configured to generate the time-varying signal, the driver circuit comprising;

a switch configured to control the time-varying signal in response to a control signal;

a second capacitor coupled in parallel with the switch; and

a second inductor coupled to the switch and the second capacitor.

2. The wireless power transmitter of claim 1, wherein the transmit circuit is coupled in parallel with the driver circuit.

3. The driver circuit of claim 2, further comprising a third capacitor coupled in series with the transmit circuit.

4. The wireless power transmitter of claim 1, wherein the driver circuit is configured as a class-E driver circuit.

5. The wireless power transmitter of claim 4, wherein a quality factor of the driver circuit comprises at least 1.79.

6. The wireless power transmitter of claim 1, further comprising a supply voltage coupled in series with the second inductor.

7. A method for transmitting wireless power, comprising:

transmitting power wirelessly, by a transmit circuit, in response to a time-varying signal, the transmit circuit configured as a resonant tank comprising a first capacitor coupled with a first inductor; and

generating, by a driver circuit, the time-varying signal, the driver circuit comprising a switch configured to control the time-varying signal in response to a control signal, a second capacitor coupled in parallel with the switch, and a second inductor coupled to the switch and the second capacitor.

8. The method of claim 7, wherein the transmit circuit is coupled in parallel with the driver circuit.

9. The method of claim 8, wherein a third capacitor is coupled in series with the transmit circuit.

10. The method of claim 7, wherein the driver circuit is configured as a class-E driver circuit.

11. The method of claim 10, wherein a quality factor of the driver circuit comprises at least 1.79.

12. The method of claim 7, further comprising supplying, by a supply voltage, power to the driver circuit, wherein the supply voltage is coupled in series with the second inductor.

13. A driver circuit for use in wireless power transfer, comprising:

means for transmitting power wirelessly in response to a time-varying signal, the means for transmitting comprising means for storing energy in a first electric field coupled with means for storing energy in a first magnetic field; and

means for generating the time-varying signal, the means for generating comprising a means for controlling the time-varying signal in response to a control signal, means for storing energy in a second electric field coupled in parallel with the means for controlling, and means for storing energy in a second magnetic field coupled to the means for controlling and the means for storing energy in the second electric field.

14. The driver circuit of claim 13, wherein the means for transmitting is coupled in parallel with the means for generating.

15. The driver circuit of claim 14, wherein means for storing energy in a third electric field is coupled in series with the means for transmitting.

16. The driver circuit of claim 13, wherein the means for generating is configured as a class-E driver circuit.

17. The driver circuit of claim 16, wherein a quality factor of the means for generating comprises at least 1.79.

18. The driver circuit of claim 13, further comprising means for supplying power to the means for generating, wherein the means for supplying power is coupled in series with the means for storing energy in the second magnetic field.