STORAGE CABINET WITH IMPROVED RFID ANTENNA SYSTEM

• US 20070046552A1
• Filed: 07/10/2006
• Published: 03/01/2007
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Stanley Black & Decker, Inc.
• Inventors: Marino, Ronald
• Granted Patent: US 7,648,065 B2
• Time in Patent Office: Days
• US Class Current: 343/720
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 50/28 Logistics, e.g. warehousing, loading, distribution or shipping
• CPC Class Codes: G16H 40/20 for the management or administration of healthcare resources or facilities, e.g. managing hospital staff or surgery rooms
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A system for reading RFID tags of articles within a cabinet includes a repositionable shelf. The repositionable shelf includes an antenna assembly having three antenna pairs. Each antenna pair has a loop antenna and a figure eight antenna. The antenna pairs are on a PC board. The PC board includes an RJ45 connector which provides both power to the antenna assembly as well as a communication interface for the antenna assembly. The RJ45 connector could be used to provide the RF signals from the antenna to a reader. The system could also include a repositionable divider for placement perpendicular to the repositionable shelf. The repositionable divider also includes a loop antenna and a figure eight antenna.

Claims

1. An antenna assembly for use with a reader to detect a plurality of RFID tags comprising:

a first antenna being closed so as to have a first perimeter and extending along a first axis; and

a second antenna extending along the first axis, the first antenna located within the first perimeter and the second antenna being proximal to the first antenna, the second antenna being of a type such that it is isolated from the first antenna.

2. The antenna assembly of claim 1 where the second antenna is isolated from the first antenna by about 20 dB.

3. The antenna assembly of claim 1 where the first antenna and the second antenna are generally coplanar in a first plane, and the second antenna is symmetrically positioned within the first antenna.

4. The antenna assembly of claim 3 further comprising a third antenna, the third antenna extending along a second axis in a second plane, the first plane being parallel to the second plane, and the first axis being perpendicular to the second axis.

5. The antenna assembly of claim 4 further comprising a fourth antenna and a fifth antenna, the fifth antenna located within the perimeter of the fourth antenna, the fifth antenna placed symmetrically within the fourth antenna such that the fifth antenna is isolated from the fourth antenna.

6. The antenna assembly of claim 5 where the fourth antenna and the fifth antenna extend generally along a third axis, the third axis being parallel to the first axis and perpendicular to the second axis.

7. The antenna assembly of claim 6 further comprising a sixth antenna and a seventh antenna, the sixth antenna and the seventh antenna located within the first perimeter, the seventh antenna positioned symmetrically within the sixth antenna such that the sixth antenna is isolated from the seventh antenna.

8. The antenna assembly of claim 7 further comprising an eighth antenna, the eighth antenna being coplanar with the third antenna and extending along a fourth axis, the fourth axis parallel to the first axis.

9. The antenna assembly of claim 8 where the first antenna, the second antenna, the third antenna, the fourth antenna, the fifth antenna, the sixth antenna, the seventh antenna and the eighth antenna are placed on a printed circuit board.

10. The antenna assembly of claim 9 where the first antenna, the second antenna, the fourth antenna, the fifth antenna, the sixth antenna and the seventh antenna are on a first side of the printed circuit board, and the third antenna and the eighth antenna are on a second side of the printed circuit board.

11. The antenna assembly of claim 10 where the first antenna, the fourth antenna and the sixth antenna are loop antennas.

12. The antenna assembly of claim 11 where the second antenna, the third antenna, the fifth antenna, the seventh antenna, and the eighth antenna are figure eight antennas.

13. The antenna assembly of claim 1 where the first antenna and the second antenna have antenna elements, and the antenna elements of the first antenna and the second antenna have a first width.

14. An antenna assembly for use with a reader to detect a plurality of RFID tags comprising:

a first antenna being closed so as to have a first perimeter;

a second antenna positioned symmetrically within the first perimeter;

a first tuning capacitance for tuning the first antenna; and

a second tuning capacitance for tuning the second antenna.

15. The antenna assembly of claim 14 further comprising:

a third antenna, the third antenna being coplanar with the first antenna and positioned within the first perimeter, the third antenna being smaller than the first antenna, the third antenna having a third antenna element; and

a third tuning capacitance for tuning the third antenna, where the width of third antenna element is chosen so that first tuning capacitance is approximately the same as the first tuning capacitance.

16. A system for tracking articles having RFID tags within a cabinet comprising:

a repositionable shelf having a first antenna assembly, the repositionable shelf extending generally horizontally, the repositionable shelf having a power input and a data connector, the data connector for connection to an RFID reader; and

a divider having a second antenna assembly, the divider extending generally vertically, the repositionable enclosure having a power input and a data connector, the data connector for connection to the RFID reader.

17. The system of claim 16 where the divider is repositionable.

18. The system of claim 17 further where the first antenna assembly has a first antenna pair in a shelf plane, and the second antenna assembly has a second antenna pair in a divider plane, and the shelf plane is perpendicular to the divider plane.

19. The system of claim 18 where the first antenna pair extend along a first antenna pair axis, the second antenna pair extend along a second antenna pair axis, and the first antenna assembly includes a first antenna extending along an first antenna axis, the first antenna axis being generally perpendicular to the first antenna pair axis and the second antenna pair axis.

20. The system of claim 19 where the first antenna assembly includes a third antenna pair, the third antenna pair being generally coplanar with the first antenna pair.

21. The system of claim 20 where the first antenna assembly includes a fourth antenna pair, the fourth antenna pair being generally coplanar with the first antenna pair.

22. The system of claim 21 further comprising a second antenna coplanar with the first antenna.

23. The system of claim 22 where the first antenna pair comprise a first loop antenna and a first figure eight antenna.

24. The system of claim 23 where the second antenna pair comprise a second loop antenna and a second figure eight antenna.

25. The system of claim 24 where the first antenna is a loop antenna and the second antenna is a figure eight antenna.

26. A repositionable shelf for use within a cabinet comprising:

an antenna assembly; and

a connector providing a data interface for the antenna assembly so as to allow an RFID reader to read data from the antenna assembly and for providing power to the antenna assembly.

27. The repositionable shelf of claim 26 where the connector has a plurality of lines, and a first subset of the plurality of lines provides power to the antenna assembly while a second subset of the plurality of lines is the data interface.

28. The repositionable shelf of claim 27 where the antenna assembly where the connector is an RJ45 connector.

29. A cabinet comprising:

a plurality of repositionable shelves, and at least one of the repositionable shelves having an RFID antenna assembly, the RFID antenna assembly having a first antenna and a second antenna, the second antenna positioned so as to be symmetrical with respect to the first antenna.

30. The cabinet of claim 29 where the first antenna is a loop antenna and the second antenna is a figure eight antenna.

31. The cabinet of claim 29 where the first antenna is a figure eight antenna and the second antenna is a loop antenna.