Energy harvesting circuit

• US 7,084,605 B2
• Filed: 10/18/2004
• Issued: 08/01/2006
• Est. Priority Date: 10/29/2003
• Status: Active Grant

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University Of Pittsburgh (University of Pittsburgh of The Commonwealth System of Higher Education)
• Inventors: Mickle, Marlin H., Capelli, Christopher C., Swift, Harold
• Primary Examiner(s): Phan, Tho
• Assistant Examiner(s): Tran, Chuc
• Application Number:
  US10/967,833
• Publication Number:
  US 20050104553A1
• Time in Patent Office: 652 Days
• Field of Search: 320/101, 320/104, 320/108, 320/109, 343/850, 343/703, 343/701, 343/722, 343/741, 343/860
• US Class Current: 320/101
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A station having a means for receipt of ambient energy from the environment and energizing power storage devices of objects of interest comprising one or more antennae and circuitry for converting said ambient energy into DC power for energizing said power storage devices. The circuitry for converting the ambient energy into DC power may include a rectifier/charge pump. The antenna of the station is tuned to maximize DC energy at the output of the rectifier/charge pump. The station can be used to energize power storage devices including capacitors and batteries that are used in electronic devices, such as cell phones, cameras, PDAs. Various antenna constructions may be employed.

Claims

1. A remote station for receiving ambient energy from the environment and energizing one or more power storage devices of an object of interest comprising:

one or more antennae, each of said antennae harvesting RF energy from said ambient energy,

one or more conversion circuits, each of said conversion circuits generating a DC signal for energizing said one or more power storage devices by converting the RF energy harvested by a respective one of said one or more antennae into DC energy, and

one or more tuning circuits, each of said tuning circuits being electrically connected to a respective one of said one or more antennae to tune said respective one of said one or more antennae in order to maximize the DC signal generated from the RF energy harvested by said respective one of said one or more antennae.

2. The remote station of claim 1 wherein said one or more antennae is a plurality of antennae, wherein said one or more conversion circuits is a plurality of conversion circuits, and wherein said one or more tuning circuits is a plurality of tuning circuits.

3. The remote station of claim 2 wherein each of the DC signals generated by said conversion circuits are combined in series to obtain a higher voltage.

4. The remote station of claim 2 wherein each of said tuning circuits comprises an LC circuit.

5. The remote station of claim 2 wherein each of said antennae is tuned to a different frequency so as to harvest energy from a broadband RF spectrum, said RF energy harvested by each one of said antennae being of the frequency to which said one of said antennae is tuned.

6. The remote station of claim 2 wherein each of said antennae is a broadband antennae tuned to a different frequency spectrum so as to harvest energy from a broadband RF spectrum, said RF energy harvested by each one of said antennae being of the frequency spectrum to which said one of said antennae is tuned.

7. The remote station of claim 2 wherein said ambient energy comprises a frequency spectrum and wherein each of said antennae is tuned to the same frequency or portion of the frequency spectrum.

8. The remote station of claim 1 wherein the ambient energy is RF power.

9. The remote station of claim 2 wherein each of said antennae is a wideband antenna for substantially continuous coverage of about 20 KHz to 30 MHz radio frequency spectrum.

10. The remote station of claim 2 wherein each of said antennae is a wideband antenna for continuous coverage of about 1.5 MHz to 30 MHz radio frequency spectrum.

11. The remote station of claim 2 wherein each of said antennae is a wideband antenna for continuous coverage of about 30 MHz to 3 GHz radio frequency spectrum.

12. The remote station of claim 2 wherein each of said antennae generally occupy a fixed geographic area.

13. The remote station of claim 12 wherein each said fixed geographic area is included within a certain fixed area.

14. The remote station of claim 2 wherein each of said conversion circuits includes a rectifier/charge pump.

15. A remote station for receipt of ambient energy from the environment and energizing one or more power storage devices of an object of interest comprising

at least two antennae, each of said antennae harvesting RF energy from said ambient energy,

an RF combining device electrically connected to each of said antennae, said RF combining device generating a combined RF signal from the RF energy harvested by each of said antennae, and

circuitry for convening said combined RF signal into DC power for energizing said one or more power storage devices,

wherein said RF combining device tunes a combination of said antennae in a manner that maximizes said DC power.

16. The remote station of claim 15 wherein said RF combining device comprises an RF combiner.

17. The remote station of claim 15 wherein said RF combining device comprises a balun.

18. The remote station of claim 15 wherein each of said antennae is tuned to a different frequency so as to harvest energy from a broadband RF spectrum.

19. The remote station of claim 15 wherein each of said antennae is a broadband antennae tuned to a different frequency spectrum so as to harvest energy from a broadband RF spectrum.

20. The remote station of claim 15 wherein said ambient energy comprises a frequency spectrum and wherein each of said antennae is tuned to the same frequency or portion of the frequency spectrum.

21. A remote station for receiving ambient energy from the environment and providing energy to objects of interest comprising

at least one antenna,

circuitry for converting said ambient energy into DC power,

at least two power storage devices, a first one of said power storage devices being electrically connected to said circuitry, and

a switch for selectively electrically connecting said first one of said power storage devices to a second one of said power storage devices.

22. The remote station of claim 21 wherein

said first and second ones of said power storage devices have different charging dynamics.

23. The remote station of claim 22 wherein said power storage devices are capacitors.

24. A remote station for receiving ambient energy from the environment and energizing one or more power storage devices of an object of interest comprising

at least one antenna,

circuitry for converting said ambient energy into DC power for energizing said one or more power storage devices,

a tuning mechanism electrically connected to said at least one antenna and said circuitry, and

a feedback device for providing feedback to the tuning mechanism to adjust the tuning mechanism for a higher level of energy harvesting.