RFID SYSTEM WITH DISTRIBUTED READERS

• US 20090267737A1
• Filed: 04/29/2008
• Published: 10/29/2009
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Zest Labs, Inc.
• Original Assignee: Intelleflex Corporation
• Inventors: Farrell, Edward M., Kawaguchi, Dean
• Granted Patent: US 8,717,144 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 2209/886 using energy harvesting, e.g. solar, wind or mechanical
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A system in one embodiment includes a plurality of Radio Frequency Identification (RFID) readers, each reader being capable of using a single antenna for both transmit and receive functions, wherein, during operation, one of the readers transmits and at least another of the readers receives a response to the transmission from an RFID device. A system in another embodiment includes a plurality of Radio Frequency Identification (RFID) readers, each reader having at least one antenna mounted on a housing thereof, wherein, during operation, the reader transmitting emits a signal sufficient to communicate with a battery assisted passive RFID device at a range of at least 20 meters. Additional systems and methods are also presented.

Claims

1. A system, comprising:

a plurality of Radio Frequency Identification (RFID) readers, each reader being capable of using a single antenna for both transmit and receive functions,

wherein, during operation, one of the readers transmits and at least another of the readers receives a response to the transmission from an RFID device.

2. The system as recited in claim 1, wherein the transmitting reader emits a signal sufficient to communicate with a battery assisted passive RFID tag at a range of at least 20 meters.

3. The system as recited in claim 1, wherein the single antenna of at least one of the readers is mounted on a housing thereof.

4. The system as recited in claim 1, wherein each of the readers has only the single antenna coupled thereto.

5. The system as recited in claim 4, wherein the single antenna of each reader is located remotely from a housing of the reader.

6. The system as recited in claim 1, wherein each of the readers has only one antenna port.

7. The system as recited in claim 1, wherein the antenna of at least one of the readers is omnidirectional.

8. The system as recited in claim 1, wherein the antenna of at least one of the readers is directional.

9. A system, comprising:

a plurality of Radio Frequency Identification (RFID) readers, each reader having at least one antenna mounted on a housing thereof.

wherein, during operation, the reader transmitting emits a signal sufficient to communicate with a battery assisted passive RFID device at a range of at least 20 meters.

10. The system as recited in claim 9, wherein the antenna of at least one of the readers is mounted on a housing thereof.

11. The system as recited in claim 9, wherein each of the readers has only one antenna.

12. The system as recited in claim 9, wherein each of the readers has only one antenna port.

13. The system as recited in claim 9, wherein the antenna of at least one of the readers is omnidirectional.

14. The system as recited in claim 9, wherein the antenna of at least one of the readers is directional.

15. A method, comprising:

instructing one Radio Frequency Identification (RFID) reader to transmit;

receiving information from a plurality of RFID readers corresponding to a signal from an RFID device received by the plurality of readers, each of the readers independently processing the signal from the RFID device, the information including a characteristic of the signal from the RFID device;

selecting at least one of the readers from which the information is received based on the information; and

processing additional information received from the selected at least one of the readers and corresponding to the signal from the RFID device.

16. The method as recited in claim 15, wherein the characteristic of the signal includes a representation of a strength of the signal.

17. The method as recited in claim 15, further comprising:

selecting multiple readers;

processing the additional information received from the selected readers and corresponding to the signal from the RFID device; and

performing error correction on data sent by the RFID device using the processed information from the selected readers.

18. The method as recited in claim 17, wherein all readers receiving the signal are selected.

19. The method as recited in claim 15, further comprising selecting at least one of the readers as a new transmitter for further communication with the RFID device.

20. The method as recited in claim 15, further comprising detecting movement of the RFID device by analyzing a difference in frequency of the RFID device signal received by different readers.

21. The method as recited in claim 15, further comprising instructing the receiving readers to listen for backscatter on a frequency used by the transmitting reader.

22. The method as recited in claim 15, wherein the at least one of the selected readers locks onto a frequency of a carrier signal generated by the transmitting reader, wherein the carrier signal from the transmitting reader is received and analyzed directly by the at least one of the selected readers.

23. A method, comprising:

instructing one Radio Frequency Identification (RFID) reader to transmit;

receiving information from a plurality of RFID readers, the information corresponding to a signal from an RFID device received by the plurality of readers, each of the readers independently processing the signal from the RFID device, the information including a characteristic of the signal from the RFID device;

selecting a new reader to transmit based on the information; and

instructing the new reader to transmit to the RFID device.

24. The method as recited in claim 23, further comprising detecting movement of the RFID device by analyzing a difference in frequency of the RFID device signal received by different readers.