Wireless power transfer
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.
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.