POWER TRANSMISSION USING WIRELESS COMMUNICATION SIGNALS

• US 20170208597A1
• Filed: 09/04/2015
• Published: 07/20/2017
• Est. Priority Date: 09/05/2014
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Kellogg, Bryce, Gollakota, Shyamnath, Ransford, Ben, Naderiparizi, Saman, Talla, Vamsi, Smith, Joshua R.
• Granted Patent: US 10,383,126 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• 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: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 47/6255 queue load conditions, e.g. longest queue first
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/0221 power availability or consumption
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Examples described herein include wireless transmitters configured for power transmission. Example wireless transmitters may insert power packets into wireless communications such that power harvesting circuitry may harvest sufficiently continuous power from the wireless communication signals. Example power harvesting circuitry is configured to harvest power across multiple wireless communication channels. Example chargers are described which may harvest power from wireless communication signals (e.g. Wi-Fi signals).

Claims

1. A method comprising:

detecting, at a wireless transmitter, wireless communication traffic is below a threshold traffic level; and

when the wireless communication traffic is below the threshold level, transmitting power packets over multiple communication channels.

2. The method of claim 1 wherein detecting comprises accessing a number of packets in a queue of the wireless transmitter.

3. The method of claim 2 further comprising inserting the power packets in the queue when the number of packets in the queue is below the threshold level.

4. The method of claim 1 wherein the power packet comprises a UDP broadcast packet.

5. The method of claim 1 further comprising using the wireless transmitter to perform transmitting the power packets.

6. The method of claim 4 wherein the wireless transmitter is configured to transmit data signals using a first antenna and wherein the wireless transmitter is further configured to transmit the power packets using a second antenna.

7. The method of claim 1 further comprising using the wireless transmitter transmit data signals and using another device to perform transmitting the power packets.

8. The method of claim 1 wherein the wireless transmitter is configured to transmit a Wi-Fi signal.

9. The method of claim 1 wherein a number or data rate of the power packets is selected based at least in part on electrical characteristics of harvesting circuitry configured to harvest power from the power packets.

10. The method of claim 9 further comprising a control loop whereby the wireless transmitter selects the number or data rate of the power packets based at least in part on the electrical characteristics.

11. A device comprising:

at least one antenna;

a queue configured to store packets for data transmission from the at least one antenna in accordance with a wireless communication technique; and

at least one computer readable media encoded with executable instructions that, when executed by at least one processing unit, cause the device to insert power packets in the queue when fewer than a threshold number of packets are stored in the queue for data transmission.

12. The device of claim 11, wherein the threshold number is based, at least in part, on electrical characteristics of power harvesting circuitry configured to receive transmissions from the device.

13. The device of claim 11, wherein the power packets are configured for transmission on multiple communication channels.

14. The device of claim 13, wherein the multiple communication channels each correspond with different frequencies.

15. The device of claim 13, wherein the multiple communication channels are distinguished spatially using multiple antennas.

16. The device of claim 11, wherein the power packets comprise UDP broadcast packets.

17. The device of claim 11, wherein the data transmission comprises Wi-Fi data transmission.

18. A device comprising:

an antenna;

power harvesting circuitry coupled to the antenna, wherein the power harvesting circuitry is configured to harvest power from multiple channels of wireless communication signals received at the antenna, wherein the wireless communication signals include data packets and power packets inserted into the wireless communication signals; and

an electrical interface coupled to the power harvesting circuitry and configured to provide the power to an electrical device.

19. The device of claim 18, wherein the power harvesting circuitry includes a rectifier coupled to a DC-DC converter.

20. The device of claim 19 wherein components of the rectifier and DC-DC converter are selected based on an impedance variation across frequencies of a combination of the rectifier and DC-DC converter.

21. The device of claim 20, wherein the power harvesting circuitry further comprises a matching network configured to match an impedance of the antenna to an impedance of the combination of the rectifier and the DC-DC converter.

22. The device of claim 18, wherein the electrical interface comprises a USB interface.

23. The device of claim 18, wherein the device is further configured to transmit signals using the antenna in accordance with backscatter communication techniques.