Wireless power transmission system
The wireless power transmission is a system for providing wireless charging and/or primary power to electronic/electrical devices via microwave energy. The microwave energy is focused to a location by a power transmitter having one or more adaptively-phased microwave array emitters. Rectennas within the device to be charged receive and rectify the microwave energy and use it for battery charging and/or for primary power.
1. A wireless power transmitter, comprising:
a phased array antenna array; and
at least one controller that is communicatively coupled to phased array antenna array;
wherein the at least one controller is configured to:
perform a first instance of a phase tuning process to determine phases of power transmission signals based on a first instance of multipath calibration signals received from a device to be charged,
transmit, using the phased array antenna array, the power transmission signals to the device to be charged based on the phases of power transmission signals determined by the first instance of the phase tuning process,
perform a second instance of the phase tuning process to determine phases of the power transmission signals based on a second instance of the multipath calibration signals received from the device to be charged, wherein the second instance of the multipath calibration signals are received in response to the device to be charged receiving the power transmission signals,
transmit, using the phased array antenna array, the power transmission signals to the device to be charged based on the phases of power transmission signals determined by the second instance of the phase tuning process,
determine a delay until performing a third instance of the phase tuning process, by comparing a power level of the first instance and the second instance of the multipath calibration signals, and
perform the third instance of the phase tuning process after the delay has elapsed;
wherein the phase tuning process includes:
detecting a phase at which each signal of a respective multipath calibration signals are received by the phased array antenna, and
determining the phases of the power transmission signals based on a complex conjugate of the phase at which each signal of the respective multipath calibration signals are detected.
2. The wireless power transmitter of claim 1 , wherein the delay is increased when the power level of the first instance and the second instance of the multipath calibration signals are within a predetermined threshold.
3. The wireless power transmitter of claim 1 , wherein the delay is decreased when the power level of the first instance and the second instance of the multipath calibration signals are exceeds a predetermined threshold.
4. The wireless power transmitter of claim 1 , wherein the delay is determined so that instances of the phase tuning process occur a minimum of 10 times per second.
5. The wireless power transmitter of claim 1 , wherein the delay is determined so that instances of the phase tuning process occur a maximum of 500 times per second.
6. The wireless power transmitter of claim 1 , wherein the phases of the power transmission signals determined by the phase tuning process are at a phase angle within a margin of deviation from the complex conjugate of the phases at which each signal of the respective multipath calibration signals are detected.
7. The wireless power transmitter of claim 1 , wherein the phases of the power transmission signals determined by the phase tuning process are at a phase angle within plus or minus 36 degrees of the complex conjugate of the phase at which each signal of the respective multipath calibration signals are detected.
8. The wireless power transmitter of claim 1 wherein the phases of the power transmission signals determined by the phase tuning process are optimal for delivering power to the device to be charged.
9. The wireless power transmitter of claim 1 , wherein a frequency of the power transmission is at microwave frequencies.
10. The wireless power transmitter of claim 1 , wherein individual antenna elements of the phased array antenna array arranged in a non-planar form.
11. A method of wirelessly transmitting power, the method comprising:
performing, by a controller, a first instance of a phase tuning process to determine phases of power transmission signals based on a first instance of multipath calibration signals received from a device to be charged,
transmitting, by the controller using a phased array antenna array, the power transmission signals to the device to be charged based on the phases of power transmission signals determined by the first instance of the phase tuning process,
performing, by the controller, a second instance of the phase tuning process to determine phases of the power transmission signals based on a second instance of the multipath calibration signals received from the device to be charged, wherein the second instance of the multipath calibration signals are received in response to the device to be charged receiving the power transmission signals,
transmitting, by the controller using the phased array antenna array, the power transmission signals to the device to be charged based on the phases of power transmission signals determined by the second instance of the phase tuning process,
determining, by the controller, a delay until performing a third instance of the phase tuning process, by comparing a power level of the first instance and the second instance of the multipath calibration signals, and
performing, by the controller, the third instance of the phase tuning process after the delay has elapsed;
wherein the phase tuning process includes:
detecting a phase at which each signal of a respective multipath calibration signals are received by the phased array antenna, and
determining the phases of the power transmission signals based on a complex conjugate of the phase at which each signal of the respective multipath calibration signals are detected.
12. The method of claim 11 , wherein the delay is increased when the power level of the first instance and the second instance of the multipath calibration signals are within a predetermined threshold.
13. The method of claim 11 , wherein the delay is decreased when the power level of the first instance and the second instance of the multipath calibration signals are exceeds a predetermined threshold.
14. The method of claim 11 , wherein the delay is determined so that instances of the phase tuning process occur a minimum of 10 times per second.
15. The method of claim 11 , wherein the delay is determined so that instances of the phase tuning process occur a maximum of 500 times per second.
16. The method of claim 11 , wherein the phases of the power transmission signals determined by the phase tuning process are at a phase angle within a margin of deviation from the complex conjugate of the phases at which each signal of the respective multipath calibration signals are detected.
17. The method of claim 11 , wherein the phases of the power transmission signals determined by the phase tuning process are at a phase angle within plus or minus 36 degrees of the complex conjugate of the phase at which each signal of the respective multipath calibration signals are detected.
18. The method of claim 11 wherein the phases of the power transmission signals determined by the phase tuning process are optimal for delivering power to the device to be charged.
19. The method of claim 11 , wherein a frequency of the power transmission is at microwave frequencies.
20. The method of claim 11 , wherein individual antenna elements of the phased array antenna array arranged in a non-planar form.