Distributed RF coupled system

• US 7,026,936 B2
• Filed: 09/30/2003
• Issued: 04/11/2006
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: Smartrac Technology Fletcher, Inc. (Avery Dennison Corporation)
• Original Assignee: ID Solutions Incorporated
• Inventors: Roesner, Bruce B.
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/676,226
• Publication Number:
  US 20050068179A1
• Time in Patent Office: 924 Days
• Field of Search: 340/505, 340/506, 340/517, 340/521, 340/531, 340/533, 340/538, 340/539.1, 340/572.1, 340/575.7, 340/572.8, 340/310.01, 340/825.36, 345/211
• US Class Current: 340/572.4
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil

Abstract

An RFID sensor system and method is disclosed. An RFID sensor system includes a conducting path having first and second conductors, and one or more RFID sensing transceivers spatially-distributed along the conducting path and capactively-coupled to the first and second conductors. The system further includes a controller that provides an AC signal on the conducting path, and receives signals from the one or more RFID sensing transceivers. The conducting path and RFID sensing transceivers can formed in a flexible substrate and mated together.

Claims

1. A radio frequency identification (RFID) sensor system comprising:

multiple spatially-distributed RFID sensing transceivers;

first and second conductive paths, far receiving sensing signals from the RFID sensing transceivers; and

a controller for providing a carrier signal on the first and second conductive pats, and for receiving the signals from the first and second conductive paths;

wherein the spatially-distributed RFID sensing transceivers are non-inductively coupled, in parallel, to the first and second conductive paths.

2. The system in accordance with claim 1, wherein the first and second conductive paths are substantially parallel to each other.

3. The system in accordance with claim 1, wherein the controller includes an oscillator for providing an AC signal for the carrier signal.

4. The system in accordance with claim 1, further comprising a reader, in communication with the controller, and having logic for resolving an output based on the sensing signals received from the RFID sensing transceivers.

5. The system in accordance with claim 1, wherein the sensing signals are capacitively-coupled from the RFID sensing transceivers to the first and second conductive paths.

6. The system in accordance with claim 1, wherein the RFID sensing transceivers generate the sensing signals based on a stimulus perceivable by the RFID sensing transceivers.

7. The system in accordance with claim 6, wherein the stimulus is selected from the group consisting of:

pressure, light, temperature, touch, chemical composition, or biological composition.

8. A radio frequency identification (RFID) sensor system, comprising:

a conducting path having first and second conductors; and

one or more RFID sensing transceivers spatially-distributed along the conducting path and capacitively-coupled to the first and second conductors; and

a controller coupled to the conducting path.

9. The system in accordance with claim 8, wherein the controller includes an oscillator.

10. The system in accordance with claim 9, wherein the oscillator is configured to provide a carrier signal on the conducting path.

11. The system in accordance with claim 8, wherein the one or mare RFID sensing transceivers are each configured to perceive a stimulus, and provide a sensing signal to the conductive path via the capacitive coupling based on the stimulus perceived by the RFID sensing transceiver.

12. The system in accordance with claim 11, wherein the controller is configured to receive the sensing signal from an RFID sensing transceiver via the first and second conductive paths.

13. The system in accordance with claim 11, wherein the stimulus is one from the group consisting of:

pressure, light, temperature, touch, chemical composition, or biological composition.

14. The system in accordance with claim 8, wherein the first and second conductors are substantially parallel to each other.

15. A method for radio frequency identification of a stimulus, comprising:

perceiving the stimulus with at least one RFID sensing transceiver;

generating a sensing signal based on the stimulus;

capacitively coupling the sensing signal to a conductor; and

transmitting the sensing signal on the conductor to a signal reader.

16. The method in accordance with claim 15, wherein the conductor includes a first conductive pat and a second conductive path capacitively coupled to the at least one RFID sensing transceiver.

17. The method in accordance with claim 16, further comprising:

providing a carrier signal to the conductor; and

transmitting the sensing signal on the carrier signal.

18. The method in accordance with claim 17, wherein the carrier signal includes a frequency between 50 and 100 MHz.

19. The method in accordance with claim 15, further comprising resolving an output with the signal reader.

20. A system comprising:

multiple passive radio frequency identification (RFID) transceivers, each comprising a sensor;

conductors located in proximity to the passive RFID transceivers and allowing capacitance coupling between the conductors and the passive RFID transceivers; and

a controller coupled with the conductors to effect the capacitance coupling, power the passive RFID transceivers, and receive obtained sensor data from to passive RFID transceivers.

21. The system of claim 20, wherein each of the passive RFID transceivers comprises an RFID chip-attachment module and an integrated circuit (IC) chip comprising the sensor, and the conductors are located in proximity to the RFID chip-attachment modules.

22. The system of claim 21, wherein the conductors comprise first and second conductive leads.

23. The system of claim 22, further comprising at least one antenna coupled with at least one of the first and second conductive leads to allow RF transmissions with at least one external reader.

24. The system of claim 22, further comprising a printed circuit board including nodes monitored by the sensors.