Techniques for calibrating wireless power transmission systems for operation in multipath wireless power delivery environments

1. A system comprising:

a plurality of antenna elements (AEs); and

control circuitry operatively coupled to the plurality of AEs, and configured to:

determine a detected phase of a calibration signal at a first AE of the plurality of AEs;

determine a detected phase of the calibration signal at a reference AE;

direct the reference AE to continuously transmit a wireless power signal to a calibration AE at a reference phase setting;

direct the first AE to transmit a wireless power signal to the calibration AE at sequential phase settings;

collect signal information as measured by the calibration AE from each of the sequential phase settings;

determine power measurements resulting from each of the sequential phase settings based on the signal information;

process the power measurements to identify a peak power measurement;

determine a phase corresponding to the peak power measurement; and

calculate a calibration value for the first AE based on the phase of the calibration signal and the phase corresponding to the peak power measurement.

2. The system of claim 1 , wherein the reference AE comprises a feed line.

3. The system of claim 1 , wherein the control circuitry is further configured to select the reference AE from the plurality of AEs.

4. The system of claim 1 , wherein the reference phase setting comprises the detected phase of the calibration signal transmitted by the calibration AE at the reference AE minus a reference path delay phase.

5. The system of claim 1 , wherein the control circuitry is further configured to adjust a phase of the first AE based on the calibration value prior to transmitting wireless power signals.

6. The system of claim 1 , wherein the control circuitry is further configured to, for each additional AE of the plurality of AEs:

select an uncalibrated AE from the plurality of AEs;

determine a detected phase of another calibration signal at the uncalibrated AE;

determine a detected phase of the another calibration signal at the reference AE;

direct the reference AE to continuously transmit another wireless power signal to the calibration AE at another reference phase setting; and

direct the uncalibrated AE to transmit the another wireless power signal at the sequential phase settings.

7. The system of claim 6 , wherein the control circuitry is further configured to:

collect additional signal information for the uncalibrated AE as measured by the calibration AE from each of the sequential phase settings; and

determine additional power measurements resulting from each of the sequential phase settings based on the additional signal information.

8. The system of claim 7 , wherein the control circuitry is further configured to:

process the additional power measurements to identify another peak power measurement;

determine a phase corresponding to the another peak power measurement; and

calculate a calibration value for the uncalibrated AE based on the phase of the calibration signal and the phase corresponding to the another peak power measurement.

9. The system of claim 1 , wherein the plurality of AEs comprises an antenna array.

10. The system of claim 9 , wherein the antenna array comprises an adaptively-phased antenna array.

11. A method comprising:

determining a detected phase of a calibration signal at a first antenna element (AE) of a plurality of AEs;

determining a detected phase of the calibration signal at a reference AE;

directing the reference AE to continuously transmit a wireless power signal to a calibration AE at a reference phase setting;

directing the first AE to transmit a wireless power signal to the calibration AE at sequential phase settings;

collecting signal information as measured by the calibration AE from each of the sequential phase settings;

determining power measurements resulting from each of the sequential phase settings based on the signal information;

processing the power measurements to identify a peak power measurement;

determining a phase corresponding to the peak power measurement; and

calculating a calibration value for the first AE based on the phase of the calibration signal and the phase corresponding to the peak power measurement.

12. The method of claim 11 further comprising selecting the reference AE from the plurality of AEs.

13. The method of claim 11 further comprising determining the reference phase setting.

14. The method of claim 13 , wherein determining the reference phase setting comprises subtracting a reference path delay phase from the detected phase of the calibration signal transmitted by the calibration AE at the reference AE.

15. The method of claim 11 further comprising adjusting a phase of the first AE based on the calibration value prior to transmitting wireless power signals.

16. The method of claim 11 further comprising, for each additional AE of the plurality of AEs:

selecting an uncalibrated AE from the plurality of AEs;

determining a detected phase of another calibration signal at the uncalibrated AE;

determining a detected phase of the another calibration signal at the reference AE;

directing the reference AE to continuously transmit another wireless power signal to the calibration AE at another reference phase setting; and

directing the uncalibrated AE to transmit the another wireless power signal at the sequential phase settings.

17. The method of claim 16 further comprising:

collecting additional signal information for the uncalibrated AE as measured by the calibration AE from each of the sequential phase settings; and

determining additional power measurements resulting from each of the sequential phase settings based on the additional signal information.

18. The method of claim 17 further comprising:

processing the additional power measurements to identify another peak power measurement;

determining a phase corresponding to the another peak power measurement; and

calculating a calibration value for the uncalibrated AE based on the phase of the calibration signal and the phase corresponding to the another peak power measurement.

19. The method of claim 11 , wherein the plurality of AEs includes an adaptively-phased antenna array.

20. One or more non-transitory computer readable media having program instructions stored thereon which, when executed by at least one processor of a machine, cause the machine to:

determine a detected phase of a calibration signal at a first antenna element (AE) of a plurality of AEs;

determine a detected phase of the calibration signal at a reference AE;

direct the reference AE to continuously transmit a wireless power signal to a calibration AE at a reference phase setting;

direct the first AE to transmit a wireless power signal to the calibration AE at sequential phase settings;

collect signal information as measured by the calibration AE from each of the sequential phase settings;

determine power measurements resulting from each of the sequential phase settings based on the signal information;

process the power measurements to identify a peak power measurement;

determine a phase corresponding to the peak power measurement; and

calculate a calibration value for the first AE based on the phase of the calibration signal and the phase corresponding to the peak power measurement.