Decoupled RFID reader and interrogator

• US 20070046434A1
• Filed: 08/31/2006
• Published: 03/01/2007
• Est. Priority Date: 08/31/2005
• Status: Abandoned Application

• Current Assignee: GSI Group Corporation (Novanta Inc.)
• Original Assignee: SkyeTek, Inc. (RFID Holdings, Inc.)
• Inventors: Chakraborty, Sayan
• Application Number:
  US11/513,666
• Publication Number:
  US 20070046434A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• 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 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H04B 1/22 for receivers in which no local oscillation is generated
• CPC Class Codes: H04B 1/24 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/58 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa

Abstract

A decoupled RFID reader for reading an RFID tag using a single interrogator and a plurality of reader modules. The interrogator transmits an RF signal to supply power for the tag, and also sends commands to the tag. One of the reader modules communicates with the tag to trigger the tag to transmit a tag response including tag identification data. The first one of the reader modules receives the tag response and communicates the tag identification data of the tag to all of the other reader modules.

Claims

1. A decoupled RFID reader for reading an RFID tag comprising:

a single interrogator; and

a plurality of reader modules;

wherein the interrogator transmits an RF signal to supply power for the tag, and also sends commands to the tag;

wherein a first one of the reader modules communicates with the tag to trigger the tag to transmit a tag response including tag identification data and

wherein the first one of the reader modules receives the tag response and communicates the tag identification data of the tag to all of the other reader modules.

2. The decoupled RFID reader of claim 1;

wherein the tag response includes noise profile data sent from each of the plurality of reader modules to a coordinating reader/processor; and

wherein the coordinating reader/processor processes the noise profile data and sends processed data back to the reader modules to allow tuning of software filters to improve reader performance.

3. The decoupled RFID reader of claim 2, wherein the noise profile data includes at least one data type selected from the data types consisting of bit error rate, signal strength, and signal-to-noise ratio.

4. The decoupled RFID reader of claim 1, wherein the single interrogator and the plurality of reader modules function as a single logical reader.

5. The decoupled RFID reader of claim 1, wherein all tag-write functions are performed by the interrogator, and all tag-read functions are performed by certain ones of the plurality of reader modules.

6. The decoupled RFID reader of claim 1, wherein the first one of the reader modules communicates with a plurality of said RFID tags to singulate one of the tags;

and

wherein the first one of the reader modules receives the tag response from a singulated tag, and communicates the tag identification data of the singulated tag to other reader modules.

7. The decoupled RFID reader of claim 1, wherein:

a second plurality of the RFID reader modules are located in known positions, relative to each other;

noise profile data is sent from each of the second plurality of the reader modules to a coordinating reader/processor;

the tag distance from each reader is determined by the coordinating reader/processor using the noise profile data; and

a two-dimensional tag position is determined when said second plurality is equal to three, and a three-dimensional tag position is determined when said second plurality is equal to four, each said tag position being determined by the tag distance from each reader and use of a coordinated time base.

8. The method of claim 7, wherein the noise profile data includes at least one of the information types consisting of bit error rate, signal-to-noise ratio, and signal strength.

9. A decoupled RFID reader for reading an RFID tag comprising:

a single interrogator; and

a plurality of reader modules, each including a transceiver;

wherein the interrogator transmits an RF signal to supply power for the tag;

wherein more than one said transceiver in the plurality of the reader modules outputs a command, comprising an RF signal in the communication band of the tag, and receives data from the tag in response to the command; and

wherein one of the reader modules receiving the data in a tag response communicates the data from the tag to a plurality of the other reader modules, which then use this data to allow future communication with the tag.

10. The decoupled RFID reader of claim 9;

wherein the tag response includes noise profile data sent from each of the plurality of reader modules to a coordinating reader/processor; and

wherein the coordinating reader/processor processes the noise profile data and sends processed data back to the reader modules to allow tuning of software filters to improve reader performance.

11. The decoupled RFID reader of claim 10, wherein the noise profile data includes at least one data type selected from the data types consisting of bit error rate, signal strength, and signal-to-noise ratio.

12. The decoupled RFID reader of claim 9, wherein:

a second plurality of the RFID reader modules are located in known positions, relative to each other;

noise profile data is sent from each of the second plurality of the reader modules to a coordinating reader/processor;

the tag distance from each reader is determined by the coordinating reader/processor using the noise profile data; and

a two-dimensional tag position is determined when said second plurality is equal to three, and a three-dimensional tag position is determined when said second plurality is equal to four, each said tag position being determined by the tag distance from each reader and use of a coordinated time base

13. The method of claim 12, wherein the noise profile data includes at least one of the information types consisting of bit error rate, signal-to-noise ratio, and signal strength.

14. A decoupled RFID reader for reading an RFID tag comprising:

a first transmitter;

a second transmitter; and

a plurality of read-only reader modules;

wherein the first transmitter transmits an RF signal to supply power for the tag;

wherein the second transmitter transmits commands to the tag;

wherein the second transmitter communicates with the tag to trigger the tag to transmit a tag response including tag identification data; and

wherein the first one of the reader modules receives the tag response and communicates the tag identification data of the tag to all of the other reader modules.

15. The decoupled RFID reader of claim 14;

wherein the tag response includes noise profile data sent from a plurality of the reader modules to a coordinating reader/processor; and

wherein the coordinating reader/processor processes the noise profile data and sends processed data back to the reader modules to allow tuning of software filters to improve reader performance.

16. The decoupled RFID reader of claim 15, wherein the noise profile data includes at least one data type selected from the data types consisting of bit error rate, signal strength, and signal-to-noise ratio;

wherein the first one of the reader modules receives the tag response from a singulated tag, and communicates the tag identification data of the singulated tag to other reader modules.

17. The decoupled RFID reader of claim 14, wherein:

a second plurality of the RFID reader modules are located in known positions, relative to each other;

noise profile data is sent from each of the second plurality of the reader modules to a coordinating reader/processor;

the tag distance from each reader is determined by the coordinating reader/processor using the noise profile data; and

a two-dimensional tag position is determined when said second plurality is equal to three, and a three-dimensional tag position is determined when said second plurality is equal to four, each said tag position being determined by the tag distance from each reader and use of a coordinated time base.

18. The method of claim 17, wherein the noise profile data includes at least one of the information types consisting of bit error rate, signal-to-noise ratio, and signal strength.

19. The decoupled RFID reader of claim 14, wherein:

at least four of the plurality of RFID reader modules are located in known positions, relative to each other; and

a three-dimensional tag position is determined using the tag distance from each reader and a coordinated time base.

20. A method for reading an RFID tag comprising:

sending a signal from a single transmitter to energize the tag, which sends a response to a plurality of networked RFID readers.

21. The method of claim 20, wherein each of the plurality of networked RFID readers is a read-only reader.

22. The method of claim 20, wherein the response includes a tag ID.

23. The method of claim 20, including communicating the response, from each of the readers receiving the response, to a single coordinating reader/processor.

24. The method of claim 20, including sending noise profile data, from each of the readers receiving the response, to a single coordinating reader/processor.

25. The method of claim 24, wherein:

the coordinating reader/processor processes the noise profile data for each of the readers sending noise profile data, and sends processed noise profile data back to each respective one of the readers; and

the noise profile data received by each of the readers is used to tune at least one software filter in each said reader.

26. The method of claim 20, wherein:

a second plurality of the RFID reader modules are located in known positions, relative to each other;

noise profile data is sent from each of the second plurality of the reader modules to a coordinating reader/processor;

the tag distance from each reader is determined by the coordinating reader/processor using the noise profile data; and

a two-dimensional tag position is determined when said second plurality is equal to three, and a three-dimensional tag position is determined when said second plurality is equal to four, each said tag position being determined by the tag distance from each reader and use of a coordinated time base.

27. The method of claim 26, wherein the noise profile data includes at least one of the information types consisting of bit error rate, signal-to-noise ratio, and signal strength.

28. The method of claim 20, wherein:

a second plurality of the RFID reader modules are located in known positions, relative to each other;

noise profile data is sent from each of the second plurality of the reader modules to a coordinating reader/processor;

the tag distance from each reader is determined by the coordinating reader/processor using the noise profile data; and

a two-dimensional tag position is determined when said second plurality is equal to three, and a three-dimensional tag position is determined when said second plurality is equal to four, each said tag position being determined by the tag distance from each reader and use of a coordinated time base.