Wireless power receiver with boost converters directly coupled to a storage element

• US 9,973,008 B1
• Filed: 12/29/2014
• Issued: 05/15/2018
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: Leabman, Michael
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US14/584,810
• Time in Patent Office: 1,233 Days
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

An enhanced receiver for wireless power transmission is disclosed. The receiver may be able to convert RF waves into continuous, stable and suitable voltage or power that can be used for charging or powering an electronic device. The receiver may include an antenna array for extracting and rectifying power from RF waves or pockets of energy. An input boost converter in the receiver may step up and stabilize the rectified voltage, while charging a storage element in the receiver. An output boost converter in the receiver may step up the output voltage of the storage element to deliver continuous and suitable power or voltage to a load. A microcontroller in the receiver may perform power measurements at different nodes or sections to adjust the operation of the input and output boost converters so that load power requirements can be satisfied at all times.

Claims

1. A unit for receiving wireless power, the unit comprising:

an electronic device; and

a wireless power receiver embedded in the electronic device and configured to provide power to the electronic device or charge a battery of the electronic device, the wireless power receiver comprising;

an antenna element configured to convert received energy from two or more radio frequency (RF) power waves into an alternating current, wherein the two or more RF power waves are transmitted by a wireless power transmitter to converge at a location of the electronic device;

a rectifier coupled to the antenna element and configured to convert the alternating current into a direct current with a first voltage;

an input boost converter coupled to the rectifier and configured to step up the first voltage to a second voltage greater than the first voltage;

a storage element directly coupled to the input boost converter and configured to store the second voltage stepped up by the input boost converter, the input boost converter being directly coupled to an input of the storage element;

an output boost converter directly coupled to an output of the storage element, the output boost converter being configured to step up the second voltage to a third voltage greater than the second voltage; and

a controller coupled to the input and output boost converters and configured to;

determine a load requirement for the electronic device, and

control operation of the input boost converter and the output boost converter based on the determined load requirement.

2. The unit of claim 1, wherein:

the wireless power receiver comprises a communication component; and

the controller is further configured to;

obtain a measurement of a voltage at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

communicate the measurement to the electronic device via the communication component.

3. The unit of claim 2, wherein the controller is further configured to control operation of at least one of the input boost converter and output boost converter based on the obtained measurement.

4. The unit of claim 2, wherein:

the wireless power receiver further comprises a respective node at each of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

the controller obtains the measurement of the voltage from a respective node at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter.

5. The unit of claim 4, wherein the controller further obtains the measurement from an analog-to-digital converter that is located at one of the respective nodes.

6. The unit of claim 1, wherein the wireless power receiver further comprises a switch, connected to an output of the output boost converter, that selectively provides the third voltage to the electronic device.

7. The unit of claim 6, wherein the controller is further configured to close the switch in accordance with a determination that the electronic device is authorized to be wirelessly charged by the wireless power transmitter.

8. The unit of claim 1, wherein the controller controls the operation of the output boost converter by adjusting a load current limit at the output boost converter.

9. The unit of claim 1, wherein the antenna element is one of a plurality of antenna elements.

10. The unit of claim 1, wherein the controller is further configured to optimize, using a maximum power point tracking technique, an amount of power the input boost converter retrieves from the antenna element.

11. A wireless power receiver, comprising:

an antenna element configured to convert received energy from two or more radio frequency (RF) power waves into an alternating current, wherein the two or more RF power waves are transmitted by a wireless power transmitter to converge at a location of an electronic device that is coupled with the wireless power receiver;

a rectifier coupled to the antenna element and configured to convert the alternating current into a direct current with a first voltage;

an input boost converter coupled to the rectifier and configured to step up the first voltage to a second voltage greater than the first voltage;

a storage element directly coupled to the input boost converter and configured to store the second voltage stepped up by the input boost converter, the input boost converter being directly coupled to an input of the storage element;

an output boost converter directly coupled to an output of the storage element, the output boost converter being configured to step up the second voltage to a third voltage greater than the second voltage; and

a controller coupled to the input and output boost converters and configured to;

determine a load requirement for the electronic device, and

control operation of the input boost converter and the output boost converter based on the determined load requirement.

12. The wireless power receiver of claim 11, wherein:

the wireless power receiver is coupled with a communication component; and

the controller is further configured to;

obtain a measurement of a voltage at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

communicate the measurement to the electronic device via the communication component.

13. The wireless power receiver of claim 12, wherein the controller is further configured to control operation of at least one of the input boost converter and output boost converter based on the obtained measurement.

14. The wireless power receiver of claim 12, wherein:

the wireless power receiver further comprises a respective node at each of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

the controller obtains the measurement of the voltage from a respective node at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter.

15. The wireless power receiver of claim 14, wherein the controller further obtains the measurement from an analog-to-digital converter that is located at one of the respective nodes.

16. The wireless power receiver of claim 11, wherein the wireless power receiver further comprises a switch, connected to an output of the output boost converter, that selectively provides the third voltage to the electronic device.

17. The wireless power receiver of claim 16, wherein the controller is further configured to close the switch in accordance with a determination that the electronic device is authorized to be wirelessly charged by the wireless power transmitter.

18. The wireless power receiver of claim 11, wherein the controller controls the operation of the output boost converter by adjusting a load current limit at the output boost converter.

19. The wireless power receiver of claim 11, wherein the antenna element is one of a plurality of antenna elements.

20. The wireless power receiver of claim 11, wherein the controller is further configured to optimize, using a maximum power point tracking technique, an amount of power the input boost converter retrieves from the antenna element.

21. A method comprising:

at a wireless power receiver including an antenna, a rectifier coupled to the antenna, an input boost converter coupled to the rectifier, a storage element directly coupled to the input boost converter, an output boost converter directly coupled to an output of the storage element, and a controller coupled to the input and output boost converters;

converting, by the antenna, received energy from two or more radio frequency (RF) power waves into an alternating current, wherein the two or more RF power waves are transmitted by a wireless power transmitter to converge at a location of an electronic device, the wireless power receiver being embedded in the electronic device;

converting, by the rectifier, the alternating current into a direct current with a first voltage;

stepping up, by the input boost converter, the first voltage to a second voltage greater than the first voltage;

storing, by the storage element, the second voltage stepped up by the input boost converter, wherein the input boost converter is directly coupled to an input of the storage element;

stepping up, by the output boost converter, the second voltage to a third voltage greater than the second voltage;

determining, by the controller, a load requirement for the electronic device; and

controlling, by the controller, operation of the input boost converter and the output boost converter based on the determined load requirement.

22. The method of claim 21, wherein:

the wireless power receiver comprises a communication component; and

the method further comprises;

obtaining, by the controller, a measurement of a voltage at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

communicating, via the communication component, the measurement to the electronic device.

23. The method of claim 22, wherein the controller controls operation of at least one of the input boost converter and output boost converter based on the obtained measurement.

24. The method of claim 22, wherein:

the wireless power receiver further comprises a respective node at each of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter; and

the controller obtains the measurement of the voltage from a respective node at one of (i) the rectifier;

(ii) the input boost converter;

(iii) the storage element; and

(iv) the output boost converter.

25. The method of claim 24, wherein obtaining the measurement comprises obtaining the measurement from an analog-to-digital converter that is located at one of the respective nodes.

26. The method of claim 21, wherein:

the wireless power receiver further comprises a switch connected to an output of the output boost converter; and

the method further comprises selectively providing, via the switch, the third voltage to the electronic device.

27. The method of claim 26, further comprising, at the wireless power receiver:

closing, by the controller, the switch in accordance with a determination that the electronic device is authorized to be wirelessly charged by the wireless power transmitter.

28. The method of claim 21, wherein the controller controls the operation of the output boost converter by adjusting a load current limit at the output boost converter.

29. The method of claim 21, wherein the antenna is one of a plurality of antennas.

30. The method of claim 21, further comprising, at the wireless power receiver:

optimizing, by the controller and using a maximum power point tracking technique, an amount of power the input boost converter retrieves from the antenna.