PASSIVE RECEIVERS FOR WIRELESS POWER TRANSMISSION

• US 20100190435A1
• Filed: 08/24/2009
• Published: 07/29/2010
• Est. Priority Date: 08/25/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hanspeter, Sieber, Lukas, Cook, Nigel P.
• Granted Patent: US 8,432,070 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• 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 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 50/12 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 7/00308 Overvoltage protection

Abstract

Exemplary embodiments are directed to wireless power transfer. A wireless power transmission receiver includes a receive antenna including a parallel resonator configured to resonate in response to a magnetic near-field and couple wireless power therefrom. The receiver further includes a passive rectifier circuit coupled to the parallel resonator. The passive rectifier circuit is configured to transform a load impedance to the parallel resonator.

Claims

1. A wireless power transmission 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 passive rectifier circuit coupled to the parallel resonator, the passive rectifier circuit configured to transform a load impedance to the parallel resonator.

2. The receiver of claim 1, wherein the passive rectifier circuit is configured as a dual-diode full-wave rectifier circuit.

3. The receiver of claim 2, wherein the passive rectifier circuit is configured to transform the load impedance by stepping-up the load impedance by approximately 4-to-1 as seen at the parallel resonator.

4. The receiver of claim 2, wherein the parallel resonator includes an inductive loop and the inductive loop is DC grounded at one of its loop terminals.

5. The receiver of claim 2, wherein the parallel resonator includes an inductive loop and the inductive loop is DC grounded using a high frequency choke.

6. The receiver of claim 2, wherein the passive rectifier circuit is configured to transform the load impedance by stepping-up the load impedance by approximately 4-to-1 as seen at the parallel resonator.

7. The receiver of claim 2, wherein the parallel resonator includes an inductive loop and the inductive loop is DC grounded.

9. The receiver of claim 2, wherein the passive rectifier circuit includes at least one diode and the parallel resonator includes an inductive loop, the at least one diode is coupled to the inductive loop to DC ground the inductive loop.

10. The receiver of claim 2, wherein the passive rectifier circuit includes first and second diodes and the parallel resonator includes a inductive loop, the first and second diodes are coupled to the inductive loop to DC ground, the rectifier circuit further including first and second high frequency chokes respectively coupled in electrical series with the first and second diodes.

11. The receiver of claim 1, wherein the passive rectifier circuit is configured as a symmetric quad-diode full-wave rectifier circuit with the inductive loop DC grounded at its symmetry point.

12. The receiver of claim 11, wherein the passive rectifier circuit is configured to transform the load impedance by stepping-up the load impedance by approximately 16-to-1 as seen at the parallel resonator.

13. The receiver of claim 11, wherein the parallel resonator includes a inductive loop and the inductive loop is DC grounded using a high frequency choke.

14. The receiver of claim 11, wherein the passive rectifier circuit includes high frequency choke and the parallel resonator includes a loop inductor, the high frequency choke is coupled to the loop inductor to DC ground the loop inductor.

15. The receiver of claim 11, wherein the parallel resonator includes a double-turn inductive loop and the double-turn inductive loop is DC grounded at its symmetry point.

16. The receiver of claim 1, wherein the passive rectifier circuit is configured to transform the load impedance by approximately 1-to-1 as seen at the parallel resonator.

17. The receiver of claim 1, wherein the parallel resonator includes a capacitor and the passive rectifier circuit includes at least first and second diodes in electrical parallel to the capacitor.

8. The receiver of claim 8, wherein the passive rectifier circuit includes high frequency choke and the parallel resonator includes an inductive loop, the high frequency choke is coupled to the inductive loop to DC ground the inductive loop.

18. An electronic device, comprising a wireless power transmission receiver, including:

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

a passive rectifier circuit coupled to the parallel resonator, the passive rectifier circuit configured to transform a load impedance to the parallel resonator.

19. A method for receiving wireless power, comprising:

transforming a load impedance to a wireless power receiver resonator to improve efficiency of wireless power transmission;

resonating at the receiver resonator in response to a magnetic near-field; and

rectifying power extracted from the resonating receiver resonator.

20. The method of claim 19, wherein the transforming a load impedance and the rectifying power is performed in a same rectifying circuit.

21. The method of claim 19, wherein the rectifying uses a passive rectifier circuit configured as a dual-diode full-wave rectifier circuit.

22. The method of claim 19, wherein the rectifying uses a passive rectifier circuit configured as a symmetric quad-diode full-wave rectifier circuit.

23. A wireless power transmission receiver, comprising:

means for transforming a load impedance to a wireless power receiver resonator to improve efficiency of wireless power transmission;

means for resonating at the receiver resonator in response to a magnetic near-field; and

means for rectifying power extracted from the resonating receiver resonator.