Wireless power transmission

1. A method of wirelessly delivering power via a phased antenna array, the method comprising:

transmitting with a transmission system, a narrow beam of radio-frequency energy having a solid angle, an elevation angle, and an azimuthal angle;

receiving the narrow beam of radio-frequency energy with a power receiver and if the received radio-frequency energy is above a predetermined threshold, backscattering a portion of the received radio-frequency energy back towards the phased antenna array;

receiving the backscattered portion and determining a path loss and a phase shift associated therewith;

associating the determined path loss and phase shift with the elevation angle and azimuthal angle and storing the association in a hash table;

identifying a most efficient transmission path based on the associations stored in the hash table;

determining a set of supporting paths that constructively interfere with the most efficient path such that the supporting paths are within 10 degrees of the most efficient path and have less than 4 dB of loss relative to the most efficient path;

directing energy along the most efficient transmission path and stochastically transmitting energy along the set of supporting paths and recording the transmission efficiencies thereof;

identifying the most efficient set of supporting paths; and

phase modulating the phased antenna array to transmit energy along the most efficient transmission path and the most efficient set of supporting paths.

2. The method of claim 1 , wherein the transmission system comprises a radio-frequency power transmitter comprising:

an array of patch antennas, wherein the phased antenna array comprises the array of patch antennas;

an array of phase modulators, each phase modulator having an input port and associated with one or more of the patch antennas;

a local oscillator that provides an oscillatory signal to the input port of each of the phase modulators;

an array of amplifiers, each amplifier receiving an input from one of the phase modulators;

a microprocessor configured to interface with the array of phase modulators and control a holistic radiative power transmission vector pattern generated by the radio-frequency power transmitter.

3. The method of claim 2 wherein the array of patch antennas is a square array.

4. The method of claim 2 wherein each antenna of the array of patch antennas is resonant at 5.6 GHz.

5. The method of claim 2 wherein portions of the array of patch antennas are controlled together as a subarray.

6. The method of claim 2 wherein the oscillatory signals at the inputs to the phase modulators are in phase.

7. The method of claim 1 , wherein the power receiver is a radio-frequency power receiver comprising:

an array of passively phased, resonant antennas;

an array of resonant high frequency rectifiers configured to receive energy from the array of antennas;

local and global maximum power point tracking circuitry that is configured to dynamically match a load impedance;

a backscattering antenna configured to aid in receiver localization and receiver incident electric field phase measurements;

a DC-DC converter configured to deliver a fixed voltage determined by a load device.

8. The method of claim 7 wherein the resonant antennas of the power receiver include at least one of a monopole chip antenna, a dipole chip antenna, a printed dipole antenna, and a patch antenna.

9. The method of claim 7 wherein the antennas of the power receiver operate in the 5 GHz-band.

10. The method of claim 7 wherein at least a first portion of the antennas of the power receiver are oriented in a horizontal plane and at least a second portion of the antennas of the power receiver are oriented in a vertical plane.

11. The method of claim 1 wherein each antenna in the transmitting system is offset in phase from neighboring antennas.

12. The method of claim 1 wherein the beam is transmitted along a path involving at least one reflection.

13. The method of claim 1 , further comprising, before transmitting the narrow beam:

receiving a request for wireless power from the power receiver;

verifying that the power receiver is authorized to receive power from the transmission system;

tracking the power receiver to determine one or more paths to the power receiver; and

selecting at least one antenna from the phased antenna array, the selection being based on the determined one or more paths to the power receiver;

wherein the narrow beam is delivered from the at least one antenna.

14. The method of claim 1 , further comprising, before transmitting the narrow beam:

requesting wireless power for the power receiver;

receiving of the request by a cloud server associated with a transmitter in geographic proximity to the power receiver;

adjusting the price of wireless power based on information received from the power receiver and the number of devices requesting wireless power; and

transmitting the adjusted price to the power receiver;

wherein transmitting the narrow beam is performed upon confirmation of the adjusted price by a user of the power receiver.

15. The method of claim 14 wherein the information received from the power receiver includes power receiver battery level, power receiver battery consumption rate, user power preferences, user price preferences, or power receiver distance from the transmission system.