Charging of devices by microwave power beaming

• US 6,967,462 B1
• Filed: 06/05/2003
• Issued: 11/22/2005
• Est. Priority Date: 06/05/2003
• Status: Expired due to Fees

• Current Assignee: Nasa/Glenn Research Center (Government of the United States of America)
• Original Assignee: Nasa/Glenn Research Center (Government of the United States of America)
• Inventors: Landis, Geoffrey A.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/455,139
• Time in Patent Office: 901 Days
• Field of Search: 320/101, 320/106, 320/110, 320/108, 320/109, 322/2.R
• US Class Current: 320/101
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A system for providing wireless, charging power and/or primary power to electronic/electrical devices is described whereby microwave energy is employed. Microwave energy is focused by a power transmitter comprising one or more adaptively-phased microwave array emitters onto a device to be charged. Rectennas within the device to be charged receive and rectify the microwave energy and use it for battery charging and/or for primary power. A locator signal generated by the device to be charged is analyzed by the system to determine the location of the device to be charged relative to the microwave array emitters, permitting the microwave energy to be directly specifically towards the device to be charged. Backscatter detectors respond to backscatter energy reflected off of any obstacle between the device to be charged and the microwave array emitters. Power to any obstructed microwave array emitter is reduced until the obstruction is removed. Optionally, data can be modulated onto microwave energy beams produced by the array emitters and demodulated by the device, thereby providing means of data communication from the power transmitter to the device. Similarly, data can be modulated onto the locator signal and demodulated in the power transmitter, thereby providing means of data communication from the device to the power transmitter.

Claims

1. A system for charging of devices, comprising:

a power transmitter having a plurality of adaptively-phased microwave array emitters;

a device to be charged having one or more rectennas associated therewith; and

location determining means for determining a location of the device to be charged relative to the adaptively-phased array emitters;

wherein each individual microwave array emitter produces energy at a frequency close to, but different from that produced by any other microwave array emitter in the system.

2. A system according to claim 1, further comprising:

means for exchanging data between the power transmitter and the device to be charged.

3. A system according to claim 2, further comprising:

modulating means for modulating a data signal onto a locator signal produced by the device to be charged; and

demodulating means within the power transmitter for demodulating the data modulated onto the locator signal.

4. A system for charging of devices, comprising:

a power transmitter having one or more adaptively-phased microwave array emitters;

a device to be charged having one or more rectennas associated therewith;

location determining means for determining a location of the device to be charged relative to the adaptively-phased array emitters; and

one or more backscatter detectors associated with the adaptively-phased microwave array emitters for detecting microwave backscatter energy reflected off of any obstruction between the adaptively-phased microwave array emitters and the device to be charged.

5. A system according to claim 4, wherein:

the location determining means are employed to focus energy produced by the adaptively-phased microwave array emitters onto the device to be charged.

6. A system according to claim 4, wherein:

the location determining means further comprise;

a pilot beam emitter in the device to be charged for producing a locator signal;

a pilot beam detector in the power transmitter for detecting the locator signal; and

location detection means for analyzing the locator signal to determine the location of the device to be charged.

7. A system according to claim 4, wherein:

the adaptively-phased microwave array emitters produce continuous-wave microwave energy in the frequency range between 2 GHz and 10 GHz inclusive.

8. A system according to claim 4, wherein:

each separate adaptively-phased microwave array emitter produces microwave energy at a unique frequency close to but different from the frequency produced by any other adaptively-phased microwave array emitter in the system.

9. A system according to claim 4, further comprising:

means for reducing power transmitted by any adaptively-phased microwave array emitter for which an obstruction exists between it and the device to be charged.

10. A system according to claim 9, further comprising:

means for restoring full power to the obstructed adaptively-phased microwave array emitter upon removal of the obstruction.

11. A system according to claim 4, wherein:

the device to be charged is connected to a charging cradle/adapter within which the rectennas are disposed that receives microwave energy transmitted by the one or more adaptively-phased microwave array emitters and transfers it to the device to be charged.

12. A system according to claim 4, further comprising:

means for exchanging data between the power transmitter and the device to be charged.

13. A system according to claim 12, wherein:

the location determining means are employed to focus energy produced by the adaptively-phased microwave array emitters onto the device to be charged.

14. A system according to claim 12, wherein:

the location determining means further comprise;

a pilot beam emitter in the device to be charged for producing a locator signal;

a pilot beam detector in the power transmitter for detecting the locator signal; and

location detection means for analyzing the locator signal to determine the location of the device to be charged.

15. A system according to claim 12, further comprising:

means for reducing power transmitted by any adaptively-phased microwave array emitter for which an obstruction exists between it and the device to be charged.

16. A system according to claim 15, further comprising:

means for restoring full power to the obstructed adaptively-phased microwave array emitter upon removal of the obstruction.

17. A system according to claim 12, further comprising:

modulating means for modulating data onto microwave energy beams produced by the one or more adaptively-phased microwave array emitters; and

demodulating means for demodulating the data modulated onto the microwave energy beams.

18. A system according to claim 17, wherein:

the rectennas and demodulating means reside within the device to be charged.

19. A system according to claim 17, wherein:

the rectennas and demodulating means reside within a charger adapter/cradle to which the device to be charged is connected,

the device to be charged is situated in a charging cradle/adapter that receives microwave energy transmitted by the one or more adaptively-phased microwave array emitters and transfers it to the device to be charged.

20. A system for device charging, comprising:

a power transmitter portion further comprising;

a power source;

one or more adaptively-phased microwave array emitters;

means for receiving a location signal indicative of the location of a device to be charged;

location detection means for determining the location of the device to be charged from the locator signal;

means for focusing energy produced by the one or more adaptive-phase microwave array emitters onto the devices to be charged; and

control logic means for reducing the amount of energy produced by any obstructed adaptively phased microwave array emitter until the obstruction is removed; and

a device to be charged comprising;

a battery;

one or more rectennas for receiving and rectifying energy produced by the adaptively-phased microwave array emitters; and

charging and power control means for charging the battery from rectified energy received by the rectennas.