Wireless power transfer

• US 10,090,714 B2
• Filed: 08/19/2015
• Issued: 10/02/2018
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Bohn, Florian, Abiri, Behrooz, Hajimiri, Seyed Ali
• Primary Examiner(s): Hernandez, William
• Application Number:
  US14/830,692
• Publication Number:
  US 20160190872A1
• Time in Patent Office: 1,140 Days
• Field of Search: 307104
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A method of generating a DC power from incident RF waves, includes, in part, measuring the amount of power being received by a device generating the DC power, and controlling the phases of the RF waves being transmitted by a multitude of RF transmitters in accordance with the measured power. A programmable test load is optionally used at the device to measure the received power. The device optionally includes, an antenna, an RF-to-DC converter to generate the DC power, an impedance matching/transformation circuit, and an RF load/matching circuit.

Claims

1. A recovery unit adapted to receive a radio frequency (RF) signal and generate a DC power in response, the recovery unit comprising:

at least one antenna for receiving the RF signal;

an RF-to-DC converter generating the DC power;

an impedance matching/transformation circuit disposed between the at least one antenna and the RF-to-DC converter and adapted to provide impedance matching between the antenna and the RF-to-DC converter;

an RF load/matching circuit coupled to the RF-to-DC converter and adapted to block the RF signal from reaching an output terminal of the RF-to-DC converter;

a DC-to-DC converter coupled to the output terminal of the RF-to-DC converter; and

an amplitude/power detector.

2. The recovery unit of claim 1 wherein said amplitude/power detector is coupled to an output terminal of the at least one antenna.

3. The recovery unit of claim 1 wherein said amplitude/power detector is coupled to an input terminal of the RF-to-DC converter.

4. The recovery unit of claim 1 wherein said amplitude/power detector is coupled to the output terminal of the RF-to-DC converter.

5. The recovery unit of claim 1 further comprising:

a programmable load coupled to an input terminal of the DC-to-DC converter.

6. The recovery unit of claim 1 further comprising:

a programmable load coupled to an output terminal of the DC-to-DC converter.

7. The recovery unit of claim 1 further comprising:

a digital control block adapted to generate control signals for the recovery unit and to provide communication/control signals to a device receiving the DC power; and

an analog-to-digital converter adapted to convert an output of the amplitude/power detector to a digital signal.

8. The recovery unit of claim 1 further comprising:

a digital control block adapted to generate control signals for the recovery unit; and

a transceiver adapted to communicate with a device receiving the DC power.

9. A recovery unit adapted to receive a radio frequency (RF) signal and generate a DC power in response, the recovery unit comprising:

a plurality of recovery elements coupled to one another in parallel, each recovery element comprising;

at least one antenna for receiving the RF signal;

an RF-to-DC converter;

an impedance matching/transformation circuit disposed between the at least one antenna and the RF-to-DC converter and adapted to provide impedance matching between the antenna and the RF-to-DC converter; and

an RF load/matching circuit coupled to the RF-to-DC converter and adapted to block the RF signal from reaching an output terminal of the RF-to-DC converter;

a DC-to-DC converter coupled to an output terminal of each of the plurality of recovery elements;

an amplitude/power detector coupled to an output of the DC-to-DC converter; and

a programmable load coupled to the output of the DC-to-DC converter.

10. The recovery unit of claim 9 further comprising:

a digital control block adapted to generate control signals for the recovery unit and to provide communication/control signals to a device receiving the DC power; and

an analog-to-digital converter adapted to convert an output of the amplitude/power detector to a digital signal.

11. The recovery unit of claim 9 further comprising:

a digital control block adapted to generate control signals for the recovery unit; and

a transceiver adapted to communicate with a device receiving the DC power.

12. A recovery unit adapted to receive a radio frequency (RF) signal and generate a DC power in response, the recovery unit comprising:

a plurality of recovery elements each comprising;

at least one antenna for receiving the RF signal;

an RF-to-DC converter;

an impedance matching/transformation circuit disposed between the at least one antenna and the RF-to-DC converter and adapted to provide impedance matching between the antenna and the RF-to-DC converter; and

an RF load/matching circuit coupled to the RF-to-DC converter and adapted to block the RF signal from reaching an output terminal of the RF-to-DC converter;

a plurality of DC-to-DC converters each associated with and coupled to an output of a different one of the plurality of recovery elements, wherein output terminals of the plurality of DC-to-DC converters are coupled to a common node;

an amplitude/power detector coupled to the common node; and

a programmable load coupled to the common node.

13. The recovery unit of claim 12 further comprising:

a digital control block adapted to generate control signals for the recovery unit and to provide communication/control signals to a device receiving the DC power; and

an analog-to-digital converter adapted to convert an output of the amplitude/power detector to a digital signal.

14. The recovery unit of claim 12 further comprising:

a digital control block adapted to generate control signals for the recovery unit; and

a transceiver adapted to communicate with a device receiving the DC power.

15. A recovery unit adapted to receive a radio frequency (RF) signal and generate a DC power in response, the recovery unit comprising:

a plurality of recovery elements each comprising;

at least one antenna for receiving the RF signal;

an RF-to-DC converter;

an impedance matching/transformation circuit disposed between the at least one antenna and the RF-to-DC converter and adapted to provide impedance matching between the antenna and the RF-to-DC converter; and

an RF load/matching circuit coupled to the RF-to-DC converter and adapted to block the RF signal from reaching an output terminal of the RF-to-DC converter;

a plurality of DC-to-DC converters each associated with and coupled to an output of a different one of the plurality of recovery elements, wherein output terminals of the plurality of DC-to-DC converters are coupled to a common node;

a plurality of amplitude/power detectors each associated with and coupled to an output of a different one of the plurality of recovery elements;

a programmable load coupled to the common node.

16. The recovery unit of claim 15 further comprising:

a digital control block adapted to generate control signals for the recovery unit and to provide communication/control signals to a device receiving the DC power; and

an analog-to-digital converter adapted to convert an output of a first one of the plurality of amplitude/power detectors to a digital signal.

17. The recovery unit of claim 15 further comprising:

a digital control block adapted to generate control signals for the recovery unit; and

a transceiver adapted to communicate with a device receiving the DC power.

18. A recovery unit adapted to receive a radio frequency (RF) signal and generate a DC power in response, the recovery unit comprising:

a plurality of recovery elements coupled to one another in series, each recovery element comprising;

at least one antenna for receiving the RF signal;

an RF-to-DC converter;

an impedance matching/transformation circuit disposed between the at least one antenna and the RF-to-DC converter and adapted to provide impedance matching between the antenna and the RF-to-DC converter; and

an RF load/matching circuit coupled to the RF-to-DC converter and adapted to block the RF signal from reaching an output terminal of the RF-to-DC converter;

a DC-to-DC converter coupled to an output terminal of a last one of the plurality of recovery elements;

an amplitude/power detector coupled to an output of the DC-to-DC converter; and

a programmable load coupled to the output of the DC-to-DC converter.

19. The recovery unit of claim 18 further comprising:

a digital control block adapted to generate control signals for the recovery unit and to provide communication/control signals to a device receiving the DC power; and

an analog-to-digital converter adapted to convert an output of the amplitude/power detector to a digital signal.

20. The recovery unit of claim 18 further comprising:

a digital control block adapted to generate control signals for the recovery unit; and

a transceiver adapted to communicate with a device receiving the DC power.