Enhanced receiver for wireless power transmission

• US 9,819,230 B2
• Filed: 05/07/2014
• Issued: 11/14/2017
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: Petras, Jason, Leabman, Michael
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US14/272,179
• Publication Number:
  US 20150326069A1
• Time in Patent Office: 1,287 Days
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

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 wireless power receiver, comprising:

an antenna element configured to convert received energy from two or more radio frequency (RF) signals transmitted by a wireless power transmitter that converge at a location of the antenna element to form a constructive interference pattern into an alternating current;

a rectifier, operatively coupled to the antenna element for converting the alternating current into a direct current with a first voltage;

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

a storage element, operatively coupled to the input boost converter, the storage element being configured to receive and store the second voltage;

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

a switch, connected to an output of the output boost converter, that selectively provides the third voltage to a load of an electronic device that is coupled to the wireless power receiver; and

a controller, operatively coupled to the output boost converter, wherein the controller is configured to;

receive at least one measurement of a respective voltage level at a node located after at least one of;

(i) the rectifier;

(ii) the input boost converter; and

(iii) the storage element;

and

control operation of the input boost converter and output boost converter based, at least in part, on;

(i) the at least one measurement of the respective voltage level, and (ii) determined load requirements for the load; and

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

2. The receiver of claim 1, wherein:

the controller comprises a communication portion, and

the controller is further configured to communicate, via the communication portion, the at least one measurement of the respective voltage level at the node to the load.

3. The receiver of claim 1, wherein the controller is configured to control operation of the output boost converter by adjusting load current limits at the output boost converter.

4. The receiver of claim 1, wherein the controller is configured to optimize the amount of power the input boost converter can pull from the antenna element via maximum power point tracking.

5. The receiver of claim 1, wherein the controller is configured to:

control operation of the storage element by regulating voltage to be output from the storage element based on the least one measurement of the respective voltage level at the node.

6. The receiver of claim 1, wherein:

the controller comprises a linear voltage regulator configured to provide a steady voltage, a microcontroller, and a memory, and

the microcontroller is configured to;

(i) receive the at least one measurement of the respective voltage level at the node;

(ii) control the operation of the input boost converter and output boost converter;

(iii) open or close the switch; and

(iv) further store data pertaining to the operation and monitoring of the wireless power receiver in the memory.

7. The receiver of claim 1, wherein the antenna element comprises an antenna array.

8. The receiver of claim 1, wherein the controller receives the at least one measurement from an analog-to-digital converter that is located at the node.

9. The receiver of claim 8, wherein:

the node is one of a plurality of nodes of the wireless power receiver, each node including a respective analog-to-digital converter that provides voltage measurements to the controller, and

a respective node of the plurality of nodes is located after each of (i) the antenna element, (ii) the rectifier, (iii) the input boost converter, and (iv) the storage element.

10. The receiver of claim 1, wherein:

the storage element is disposed between the input boost converter and the output boost converter;

an input of the storage element is directly connected to an output of the input boost converter; and

an output of the storage element is directly connected to an input of the output boost converter.

11. A method for converting wirelessly received radio frequency (RF) signals into usable power, comprising:

receiving, by an antenna element of a wireless power receiver, two or more RF signals transmitted by a wireless power transmitter that converge at a location of the antenna element to form a constructive interference pattern;

converting, by the antenna element, the two or more RF into an alternating current;

converting, by a rectifier of the wireless power receiver that is operatively coupled to the antenna element, the alternating current into a direct current with a first voltage;

stepping up, by an input boost converter of the wireless power receiver that is operatively coupled to the rectifier, the first voltage to a second voltage greater than the first voltage;

storing, by a storage element of the wireless power receiver that is operatively coupled to the input boost converter, the second voltage;

stepping up, by an output boost converter of the wireless power receiver that is operatively coupled to the storage element, the second voltage to a third voltage greater than the second voltage, wherein the wireless power receiver also includes a switch that is connected to an output of the output boost converter and the switch is configured to selectively provide the third voltage to a load of an electronic device that is coupled to the wireless power receiver;

receiving, by a controller of the wireless power receiver that is operatively coupled to the output boost converter, at least one measurement of a respective voltage level at a node located after at least one of;

(i) the rectifier;

(ii) the input boost converter; and

(iii) the storage element;

controlling, by the controller, operation of the input boost converter and output boost converter based, at least in part, on;

(i) the at least one measurement of the respective voltage level, and (ii) determined load requirements for the load; and

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.

12. The method of claim 11, further comprising:

communicating the at least one measurement of the respective voltage level received at the node to the load via a communication portion in the controller.

13. The method of claim 11, further comprising controlling operation of the output boost converter via the controller by adjusting load current limits at the output boost converter.

14. The method of claim 11, further comprising optimizing, via the controller, the amount of power the input boost converter can pull from the antenna element via maximum power point tracking.

15. The method of claim 11, further comprising controlling, by the controller, operation of the storage element by regulating voltage to be output from the storage element based on the at least one measurement of the respective voltage level at the node.

16. The method of claim 11, wherein:

the controller comprises a linear voltage regulator configured to provide a steady voltage, a microcontroller, and a memory,

the microcontroller performs the operations of the controller; and

the method further comprises storing data pertaining to the operation and monitoring of the wireless power receiver in the memory.

17. The method of claim 11, wherein the antenna element comprises an antenna array.

18. The method of claim 11, wherein the controller receives the at least one measurement from an analog-to-digital converter that is located at the node.

19. The method of claim 18, wherein:

the node is one of a plurality of nodes of the wireless power receiver, each node including a respective analog-to-digital converter that provides voltage measurements to the controller, and

a respective node of the plurality of nodes is located after each of (i) the antenna element, (ii) the rectifier, (iii) the input boost converter, and (iv) the storage element.

20. The method of claim 11,

the storage element is disposed between the input boost converter and the output boost converter;

an input of the storage element is directly connected to an output of the input boost converter; and

an output of the storage element is directly connected to an input of the output boost converter.