System and method for extending range of radio frequency identification (RFID) signal communications

• US 9,070,029 B2
• Filed: 06/27/2011
• Issued: 06/30/2015
• Est. Priority Date: 06/27/2011
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Grinberg, Anatoly
• Primary Examiner(s): Lim, Steven
• Assistant Examiner(s): Knox, Kaleria
• Application Number:
  US13/169,168
• Publication Number:
  US 20120326842A1
• Time in Patent Office: 1,464 Days
• Field of Search: 340/572.7, 340/941, 340/933, 340/572.1, 340/10.4, 340/10.1, 235/385, 235/451, 235/375, 235/439, 333/167
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794

Abstract

Systems and methods for extending the range of radio frequency identification (RFID) signal communications, including related sensing systems, are disclosed. In one embodiment, the system facilitates wireless communications between a RFID reader device and RFID transponder device and includes an extender circuit. The extender circuit includes a first tank circuit including a first inductor connected in parallel with a first capacitor between first and second nodes, and a second tank circuit including a second inductor connected in parallel with a second capacitor between third and fourth nodes. The extender circuit includes a first connection including a resistor, the first connection linking the first and third nodes, and a second connection between the second and fourth nodes, where the second and fourth nodes are at or substantially at a common voltage. In at least some additional systems, the extender circuit is implemented in combination with an RFID reader or transponder device.

Claims

1. A system for facilitating wireless communications between a radio frequency identification (RFID) reader device and as RFID transponder device, the system having an extender circuit comprising:

a first tank circuit including a first inductor connected in parallel with a first capacitor between first and second nodes;

a second tank circuit including a second inductor connected in parallel with a second capacitor between third and fourth nodes;

a first connection including a resistor, the first connection linking the first and third nodes; and

a second connection between the second and fourth nodes, wherein the second and fourth nodes are at or substantially at a common voltage.

2. The system of claim 1, further comprising the RFID reader device, wherein the RFID reader device includes an RFID reading circuit in combination with a third tank circuit including a third inductor connected in parallel with a third capacitor, the RFID reader device being electrically disconnected from the extender circuit but capable of wirelessly communicating with at least a portion of the extender circuit.

3. The system of claim 1, further comprising the RFID transponder device, wherein the RFID transponder device includes an RFID transponder circuit in combination with a third tank circuit including at third inductor connected in parallel with a third capacitor, the RFID transponder device being electrically disconnected from the extender circuit but capable of wirelessly communicating with at least a first portion or the extender circuit.

4. The system of claim 3, further comprising the RFID reader device, wherein the RFID reader device includes an RFID reading circuit in combination with a fourth tank circuit including a fourth inductor connected in parallel with a fourth capacitor, the RFID reader device being electrically disconnected from the extender circuit but capable wirelessly communicating with at least a second portion of the extender circuit.

5. The system of claim 4, wherein the first portion includes the first tank circuit and the second portion includes the second tank circuit, wherein the third tank circuit is positioned so as to be within no more than about three (3) centimeters of the first tank circuit and the fourth tank circuit is positioned so as to be within no more than about three (3) centimeters of the second tank circuit.

6. The system of claim 4, wherein a distance between the first and second tank circuits is up to approximately 50 centimeters.

7. The system of claim 4, wherein a first inductance of the first inductor and a first capacitance of the first capacitor are chosen so that the first tank circuit is tuned to be resonant in relation to the third tank circuit, and a second inductance of the second inductor and a second capacitance of the second capacitor are chosen so that the second tank circuit is tuned to be resonant in relation to the fourth tank circuit, and wherein the first tank circuit is additionally resonant in relation to the second tank circuit.

8. The system of claim 1, wherein the first and second connections both include respective elongated wire portions, wherein the first and second connections can both be bent so that a path leading between the first and second tank circuits is non-linear.

9. The system of claim 8, wherein the path leading between the first and second tank circuits is substantially bent so that the first tank circuit is positioned substantially along a first side of a corner and the second tank is positioned substantially along a second side of a corner.

10. The system of claim 1, wherein the system is implemented in a rotating or rotatable head structure of a sensing system.

11. The system of claim 10, wherein the sensing system is a non-contact or interlocking switch that includes the rotating or rotatable head structure.

12. The system of claim 10, wherein the sensing system is configured to sense an opening or closing of a door with which the RFID transponder device is associated, or a passing of an object with which the RFID transponder device is associated past the sensing system as the object is carried by an assembly line.

13. The system of claim 1, wherein the system is implemented in a structure, and wherein the system allows for a presence or a position of the structure to be detected due to the wireless communications between the RFID reader device and the RFID transponder device, which occur via the system when the system passes in proximity to both of those devices.

14. The system of claim 13, wherein the system is configured to allow for sensing of the structure as it passes in proximity to both of the RFID reader and transponder devices as it is carried along a direction on an assembly line.

15. A sensing system comprising:

a radio frequency identification (RFID) reader or transponder device mounted on a first portion of the sensing system and including a first antenna device; and

a RFID extender circuit mounted on a second portion of the sensing system, the RFID extender circuit including second and third antenna devices coupled at least indirectly by way of a first connecting structure including a resistor, wherein the first antenna device includes a first tank circuit, wherein the second and third antenna devices include respectively second and third tank circuits, wherein each of the second and third tank circuits includes a respective inductor and a respective capacitor coupled in parallel between respective first and second nodes of a respective pair of nodes, wherein the respective first nodes of the respective pairs of nodes are coupled at least indirectly by way of the first connecting structure including the resistor and the respective second nodes of the respective pairs of nodes are also coupled at least indirectly with one another by way of a second connecting structure, so that the respective second nodes of the respective pairs of nodes are at or substantially at a common voltage;

wherein the second antenna device is capable of communicating with the first antenna device and the third antenna device is configured to communicate with an external device,

whereby the RFID reader or transponder device is able to detect a presence of the external device in proximity to the third antenna device by virtue of wireless communications between first and second antenna devices.

16. The sensing system of claim 15, wherein the second portion of the sensing system is rotatably mounted in relation to the first portion.

17. The sensing system of claim 15, wherein the second portion includes first and second surfaces on substantially opposite sides of the second portion, wherein the third tank circuit is positioned proximate the first surface, wherein the second tank circuit is positioned proximate the second surface, and wherein the second surface faces the first portion.

18. The sensing system of claim 15, wherein the second portion includes first and second surfaces on substantially opposite sides of the second portion, and also a third surface extending between the first and second surfaces, wherein the third tank circuit is positioned proximate the third surface, wherein the second tank circuit is positioned proximate the second surface, and wherein the second surface faces the first portion.

19. The sensing system of claim 18, wherein the first and second connecting structures are at least partly bent so as to link the third tank circuit positioned proximate the third surface and the second tank circuit positioned proximate the second surface.

20. The sensing system of claim 18, wherein the second portion with the RFID extender circuit positioned therewithin is capable of rotating and determining that the external device is located at one position around the second portion and not at another position around the second portion.

21. The sensing system of claim 15, wherein:

(a) the sensing system is a non-contact switch or interlock switch;

or

(b) the external device is one of a door and a product moving along an assembly line.

22. A method or facilitating wireless communications between a radio frequency identification (RFID) reader device and a RFID transponder device, the method comprising:

receiving a first wireless communication signal from the RFID transponder device at a first tank circuit of a RFID extender circuit, the first tank circuit having a first pair of nodes;

communicating an electrical signal based upon the received first wireless communication signal from the first tank circuit to a second tank circuit of the RFID extender circuit, the second tank circuit having a second pair of nodes, with a respective one of the second pair of nodes of the second tank circuit being electrically coupled to a respective one of the first pair of nodes of the first tank circuit at least by way of a resistor, and with respective other nodes of the first and second pairs of nodes being short-circuited so as to be at or substantially at a common voltage; and

sending a second wireless communication signal from the second tank circuit for receipt by the RFID reader device.

23. The method of claim 22, further comprising, prior to the receiving and the sending:

receiving a third wireless communication signal from the RFID reader device at the second tank circuit;

communicating a further electrical signal based upon the received third wireless communication signal from the second tank circuit to the first tank circuit electrically coupled to the second tank circuit; and

sending a fourth wireless communication signal from the first tank circuit for receipt by the RFID transponder device, whereby the RFID transponder device in response generates the first wireless communication signal.

24. The method of claim 22, further comprising:

controlling a rotational orientation of a first structure with which the RFID extender circuit is associated; and

rotating the first structure until the first tank circuit is sufficiently close to the RFID transponder device so that the first wireless communication signal occurs; and

determining at the RFID reader device, based at least partly upon the second wireless communication signal, a presence or a rotational position of the RFID transponder device.

25. The method of claim 22, further comprising, prior to the receiving of the first wireless communication signal, either (a) moving a first structure on which the RFID extender circuit is mounted through a space between the RFID reader device and the RFID transponder device, wherein the first and second wireless communication signals occur when the first structure passes through a location within the space, or (b) moving a second structure on which the RFID transponder device is mounted in relation to the RFID extender circuit, wherein the first and second wireless communication signals occur when the second structure is within a predetermined proximity of the RFID extender circuit.