RFID SYSTEM WITH IMPROVED COVERAGE AND INCREASED READING DISTANCE

• US 20130002403A1
• Filed: 11/01/2011
• Published: 01/03/2013
• Est. Priority Date: 06/30/2011
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tran, Allen Minh-Triet
• Application Number:
  US13/286,994
• Publication Number:
  US 20130002403A1
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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

A radio frequency identification (RFID) system with a parasitic element to improve coverage and increase reading distance of RFID tags is disclosed. The parasitic element may be a loop of a conductive material and is not physically connected to any circuit. One or more RFID tags may be located within a predetermined distance of the parasitic element. The parasitic element receives a first signal from an RFID reader and re-radiates the first signal. The re-radiation improves the coverage of the RFID system. An RFID tag receives the re-radiated first signal from the parasitic element and, in response, transmits a second signal. The parasitic element receives the second signal from the RFID tag and re-radiates the second signal. The RFID reader receives the re-radiated second signal from the parasitic element and reads the information sent in the second signal by the RFID tag.

Claims

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

a parasitic element configured to receive a first signal from an RFID reader and re-radiate the first signal; and

an RFID tag located within a predetermined distance of the parasitic element and configured to receive the re-radiated first signal from the parasitic element.

2. The RFID system of claim 1, wherein the RFID tag is configured to transmit a second signal that is re-radiated by the parasitic element, and wherein the RFID reader receives the re-radiated second signal from the parasitic element.

3. The RFID system of claim 1, wherein the parasitic element comprises a loop of conductive material.

4. The RFID system of claim 3, wherein the loop comprises at least one turn.

5. The RFID system of claim 3, wherein the RFID tag is located within the loop.

6. The RFID system of claim 3, wherein the loop has a shape of a square, a rectangle, a circle, an ellipse, or a polygon.

7. The RFID system of claim 3, wherein the RFID reader is located within a predetermined range of a center of the loop or a boundary of the loop.

8. The RFID system of claim 1, further comprising:

a second parasitic element configured to receive the first signal from the RFID reader and re-radiate the first signal.

9. The RFID system of claim 8, wherein the parasitic element is placed within the second parasitic element or is placed side-by-side with the second parasitic element.

10. The RFID system of claim 8, wherein the parasitic element and the second parasitic element have different orientations.

11. The RFID system of claim 1, wherein the RFID tag comprises a passive tag operating based on magnetic coupling.

12. The RFID system of claim 1, further comprising:

at least one additional RFID tag located within the predetermined distance of the parasitic element and configured to be read by the RFID reader via the parasitic element.

13. The RFID system of claim 1, wherein the RFID tag and the parasitic element are located within a container carrying an item to which the RFID tag is attached.

14. The RFID system of claim 13, wherein the container further includes the RFID reader.

15. The RFID system of claim 1, further comprising:

a plurality of RFID tags located within a container and sharing the parasitic element, the parasitic element configured to re-radiate signals for the plurality of RFID tags.

16. The RFID system of claim 1, wherein the RFID reader transmits the first signal at 13.56 MHz.

17. The RFID system of claim 1, wherein the parasitic element is not physically connected to the RFID reader or the RFID tag.

18. A method comprising:

receiving, by a radio frequency identification (RFID) tag, a first signal transmitted by an RFID reader and re-radiated by a parasitic element; and

transmitting a second signal by the RFID tag in response to the first signal, the second signal being re-radiated by the parasitic element.

19. The method of claim 18, wherein the parasitic element comprises a loop of conductive material.

20. A method comprising:

transmitting a first signal by a radio frequency identification (RFID) reader, the first signal being re-radiated by a parasitic element; and

receiving a second signal transmitted by an RFID tag and re-radiated by the parasitic element.

21. The method of claim 20, wherein the parasitic element comprises a loop of conductive material.

22. An apparatus comprising:

means for receiving a first signal transmitted by a radio frequency identification (RFID) reader and re-radiated by a parasitic element; and

means for transmitting a second signal in response to the first signal, the second signal being re-radiated by the parasitic element.

23. The apparatus of claim 22, wherein the parasitic element comprises a loop of conductive material.