Integrated rectifier and boost converter for wireless power transmission

• US 9,806,564 B2
• Filed: 05/07/2014
• Issued: 10/31/2017
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: Leabman, Michael
• Primary Examiner(s): Shin, Jeffrey
• Application Number:
  US14/272,287
• Publication Number:
  US 20150326142A1
• Time in Patent Office: 1,273 Days
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• 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: H02M 1/0022 the disturbance parameters being input voltage fluctuations
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H02M 7/05 Capacitor coupled rectifiers
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A novel integrated rectifier and boost converter circuit architecture is disclosed. The rectifier architecture includes a plurality of identical half-bridge rectifiers connected to receiving antennas to convert wireless AC power into DC power. The integrated rectifier may be coupled in series with a charging inductor in a boost converter. The inductor may discharge upon operation of two micro-controller-driven switching transistors using predetermined threshold and timing scheme to turn on/off. The rectifier architecture may provide high power densities, improve efficiency at larger load currents, and may be enabled in an integrated circuit with eight RF signal inputs, eight half-bridge rectifiers, and eight DC outputs ganged together as single feed into the boost converter. The rectifier circuit topology may include a comparator driven by the boost controller with a proprietary algorithm which suits control for a maximum power point tracking functionality, and an external micro-controller for additional control of the boost converter.

Claims

1. A receiver for providing power to a load, comprising:

a plurality of rectifiers, each connected to a common node and to a respective one of a plurality of antennas, wherein each antenna of the plurality of antennas is configured to convert electromagnetic energy from radio-frequency (RF) waves transmitted by a remote transmitter into alternating current (AC) voltage, and wherein each of the plurality of rectifiers is configured to;

convert the AC voltage received from one of the plurality of antennas to a direct current (DC) voltage; and

provide the DC voltage to the common node, wherein a first DC voltage is provided at the common node; and

a boost converter for increasing the first DC voltage to a second DC voltage, the boost converter comprising;

(i) an inductor operatively coupled to the common node and configured for receiving the first DC voltage and for providing the second DC voltage to an output terminal of the boost converter;

(ii) a microcontroller configured for controlling an amount of increase in voltage, provided from the inductor to the output terminal, from the first DC voltage to the second DC voltage; and

(iii) a comparator operatively coupled to the microcontroller and the common node, the comparator configured for comparing the first DC voltage provided at the common node with a reference voltage generated at the microcontroller,

wherein the microcontroller controls the amount of increase in voltage based on a comparison of the first DC voltage with the reference voltage performed by the comparator.

2. The receiver of claim 1, wherein:

the boost converter further comprises a plurality of transistors operatively coupled to the inductor and the microcontroller; and

the microcontroller is configured to control the amount of increase in voltage provided by the inductor to the output terminal by controlling the plurality of transistors operatively coupled to the inductor.

3. The receiver of claim 1, wherein the microcontroller is configured to provide a maximum power point tracking (MPPT) functionality to maximize the amount of voltage extracted from the RF waves and provided from the inductor to the output terminal.

4. The receiver of claim 1, further comprising a system microcontroller operatively coupled to the microcontroller, the system microcontroller being configured to control operation of the boost converter according to load requirements of an electronic device coupled to the receiver.

5. The receiver of claim 4, wherein the system microcontroller is configured to monitor power measurements in the receiver for the load for controlling operation of the boost converter.

6. The receiver of claim 5, wherein the system microcontroller is configured to communicate power measurements to the microcontroller to provide feedback to the boost converter.

7. The receiver of claim 1, wherein:

the load is for an electronic device electrically connected to the receiver; and

the amount of increase in voltage from the first DC voltage to the second DC voltage is selected by the microcontroller based at least in part on a power level required by the electronic device.

8. The receiver of claim 7, wherein:

a number of rectifiers is included in the plurality of rectifiers of the receiver so as to supply the power level required by the electronic device.

9. The receiver of claim 7, wherein the electronic device houses the receiver.

10. The receiver of claim 9, wherein each rectifier of the plurality of rectifiers is a synchronous rectifier.

11. A method for providing power in a receiver to a load, comprising:

at the receiver including a plurality of antennas, a plurality of rectifiers, a common node, and a boost converter having an inductor, a microcontroller, and a comparator operatively coupled to the common node and the microcontroller;

converting, by each of the plurality of antennas, electromagnetic energy from radio-frequency (RF) waves transmitted by a remote transmitter into alternating current (AC) voltage;

converting, by each of the plurality of rectifiers, AC voltage from one of the plurality of antennas to direct current (DC) voltage, each rectifier of the plurality of rectifiers respectively coupled to the common node and to one of the plurality of antennas;

providing DC voltage from each of the plurality of rectifiers to the common node, wherein a first DC voltage is provided at the common node;

comparing, by the comparator, the first DC voltage provided at the common node with a reference voltage generated at the microcontroller;

increasing the first DC voltage from the common node to a second DC voltage via the boost converter, wherein the inductor is operatively coupled to the common node for receiving the first DC voltage and for providing the second DC voltage to an output terminal of the boost converter; and

controlling, by the microcontroller, an amount of increase in voltage, provided to the output terminal by the inductor, from the first DC voltage to the second DC voltage, based on the comparison of the first DC voltage with the reference voltage performed by the comparator.

12. The method of claim 11, wherein:

the boost converter further comprises a plurality of transistors operatively coupled to the inductor and the microcontroller; and

controlling the amount of increase in voltage provided to the output terminal by the inductor comprises controlling the plurality of transistors operatively coupled to the inductor.

13. The method of claim 11, further comprising providing a maximum power point tracking (MPPT) functionality in the microcontroller to maximize the amount of voltage extracted from the RF waves and provided to the output terminal by the inductor.

14. The method of claim 11, further comprising controlling the operation of the boost converter according to load requirements of an electronic device coupled to the receiver via a system microcontroller operatively coupled to the microcontroller.

15. The method of claim 14, further comprising monitoring power measurements in the receiver for the load using the system microcontroller for controlling operation of the boost converter.

16. The method of claim 15, further comprising communicating power measurements from the system microcontroller to the microcontroller to provide feedback to the boost converter.

17. The method of claim 11, wherein:

the load is for an electronic device electrically connected to the receiver; and

the amount of increase in voltage from the first DC voltage to the second DC voltage is selected by the microcontroller based at least in part on a power level required by the electronic device.

18. The method of claim 17, wherein:

a number of rectifiers is included in the plurality of rectifiers of the receiver so as to supply the power level required by the electronic device.

19. The method of claim 17, wherein the electronic device houses the receiver.

20. The method of claim 19, wherein each rectifier of the plurality of rectifiers is a synchronous rectifier.