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 battery, comprising:
an antenna that receives electromagnetic energy;
circuitry that is electrically coupled to the antenna, wherein the circuitry selectively converts the electromagnetic energy received by the antenna to direct current: and
a controller that is communicatively coupled to the circuitry and the antenna, wherein the controller is configured to:
transmit, using the antenna, a first calibration signal to a wireless power transmitter,
receive, using the antenna, a first plurality of power transmission signals from a phased array antenna of the wireless power transmitter, wherein each of the first plurality of power transmission signals are transmitted at respective first phases that are determined by the first calibration signal,
transmit, using the antenna, a second calibration signal to the wireless power transmitter based on the first plurality of power transmission signals,
receive, using the antenna, a second plurality of power transmission signals from the phased array antenna of the wireless power transmitter, wherein each of the second plurality of power transmission signals are transmitted at respective second phase that are determined by the second calibration signal, and
cause the circuitry to convert the second plurality of power transmission signals to the direct current.
2. The battery of claim 1 , wherein respective first phases of each of the first plurality of power transmission signals are determined by:
detecting a phase that signal first calibration signal is received by each clement of the phased array antenna, and
calculating a complex conjugate of the phase that the first calibration signal is received by each element of the phased array antenna are detected.
3. The battery of claim 1 , wherein the controller is further configured to determine a delay before transmitting, using the antenna, a third calibration signal to the wireless power transmitter.
4. The battery of claim 3 , wherein the delay is increased when a power level of the first plurality of power transmission signals and the second plurality of power transmission signals are within a predetermined threshold.
5. The battery of claim 2 , wherein the respective first phases of the first plurality of power transmission signals are at a phase angle within a margin of deviation from a complex conjugate of a phase that the first calibration signal is received by each element of the phased array antenna.
6. The battery of claim 2 , wherein the respective first phases of the first plurality of power transmission signals are within plus or minus 36 degrees of the complex conjugate of a phase that the first calibration signal is received by each element of the phased array antenna.
7. A method of providing direct current (DC) to a device, the method comprising:
transmitting, using an antenna, a first calibration signal to a wireless power transmitter,
receiving, using the antenna, a first plurality of power transmission signals from a phased array antenna of the wireless power transmitter, wherein each of the first
plurality of power transmission signals are transmitted at respective first phases that are determined by the first calibration signal,
transmitting, using the antenna, a second calibration signal to the wireless power transmitter based on the first plurality of power transmission signals,
receiving, using the antenna, a second plurality of power transmission signals from the phased array antenna of the wireless power transmitter, wherein each of the second plurality of power transmission signals are transmitted at respective second phase that are determined by the second calibration signal, and causing circuitry to convert the second plurality of power transmission signals.
8. The method of claim 7 , wherein respective first phases of each of the first plurality of power transmission signals are determined by:
detecting a phase that signal first calibration signal is received by each clement of the phased array antenna, and
calculating a complex conjugate of the phase that the first calibration signal is received by each clement of the phased array antenna are detected.
9. The method of claim 7 , further comprising:
determining a delay before transmitting, using the antenna, a third calibration signal to the wireless power transmitter.
10. The method of claim 9 , wherein the delay is increased when a power level of the first plurality of power transmission signals and the second plurality of power transmission signals are within a predetermined threshold.