Antenna Design and Interrogator System

• US 20080252423A1
• Filed: 09/08/2006
• Published: 10/16/2008
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: SATO Holdings Corporation
• Original Assignee: Magellan Technology Pty. Ltd (SATO Holdings Corporation)
• Inventors: Littlechild, Stuart Colin, Murdoch, Graham Alexander Munro
• Granted Patent: US 7,928,847 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes 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 series of parallel spaced conductors through which currents are sequentially switched. A spatial relationship of the sequentially switched currents is chosen such that, at different times, tangential and normal magnetic fields are produced at the same location. The conductors are preferably arranged in a planar fashion and the tangential and normal magnetic fields are produced above the planar surface. A single layer of parallel spaced conductors provides substantially two dimensional operations. Adding a second parallel layer of orthogonally oriented parallel spaced conductors provides substantially three dimensional operations where currents are sequentially switched in both layers.

Claims

1. An arrangement of coils, comprising:

a first coil having first at least two first windings;

a second coil having at least a second windings; and

the second winding being juxtaposed intermediate the at least two first windings.

2. The arrangement as claimed in claim 1, further comprising:

switching means adapted to switch currents sequentially through the first winding and then the second winding.

3. The arrangement as claimed in claim 1, wherein the first and second windings are disposed in substantially a same plane.

4. The arrangement as claimed in claim 1, wherein the first windings are disposed in a plane offset from a plane of the second winding.

5. The arrangement as claimed in claim 1, wherein the first coil comprises 3 windings.

6. The arrangement as claimed in claim 1, wherein the first coil comprises 2, 3 or more than 3 windings.

7. The arrangement as claimed in claim 1, wherein the second coil comprises 2, 3 or more than 3 windings.

8. The arrangement as claimed in claim 6, wherein the first and/or second coil comprises a single layer of parallel spaced conductors for two dimensional operations.

9. The arrangement as claimed in claim 6, wherein the first and/or second coil comprises a first layer of parallel spaced conductors and a second parallel layer of orthogonally oriented parallel spaced conductors for three dimensional operations.

10. The arrangement as claimed in claim 9, wherein currents are sequentially switched in the first and second layers.

11. The arrangement as claimed in claim 1, wherein the first and second coils are disposed in a module.

12. The arrangement as claimed in claim 1, wherein the first and second windings are a series of parallel spaced conductors which, in use are adapted to produce both tangential and normal magnetic field components.

13. The arrangement as claimed in claim 2, wherein a spatial relationship of sequentially switched currents is chosen to ensure that at different times a tangential and normal magnetic fields are produced at substantially a same location.

14. The arrangement as claimed in claim 1, wherein at least a portion of the first and second coils are arranged in a planar fashion.

15. The arrangement as claimed in claim 1, wherein at least a portion of the first and second coils are arranged to produce tangential and normal magnetic fields above a planar surface.

16. An interrogator including an arrangement of coils comprising:

a first coil having first at least two first windings;

a second coil having at least a second winding; and

the second winding being juxtaposed intermediate the at least two first windings.

17. The interrogator as claimed in claim 16, further comprising a plurality of modules, at least one of the plurality of modules being arranged in an overlapping relationship with an adjacent module.

18. The interrogator as claimed in claim 17, wherein the overlapping enhances interrogation of a device in an X direction.

19. The interrogator as claimed in claim 17, wherein the overlapping enhances interrogation of a device in a Y direction.

20. The interrogator as claimed in claim 17, wherein the overlapping enhances interrogation of a device in a Z direction.

21. The interrogator as claimed in claim 16, wherein the interrogator is an RFID interrogator.

22. The interrogator as claimed in claim 16, the interrogator comprises at least one of a shelf reader, a roulette table reader, a gaming table reader, a croupiers tray reader, a document tray reader, a gem box reader, a medical cabinet reader.

23. The interrogator as claimed in claim 16, wherein the interrogator is adapted to operate in any one or any combination of X, Y and/or Z directions.

39. The interrogator as claimed in claim 17, wherein at least one module of the plurality of modules overlaps the adjacent module greater than zero and less than 50% of a module dimension.

40. The interrogator as claimed in claim 17, wherein at least one module of the plurality of modules overlaps the adjacent module greater than zero and less than 80% of a module dimension.

41. The interrogator as claimed in claim 17, wherein at least two modules of the plurality of modules are arranged in an overlapping relationship.

24. A method of energizing a first arrangement of coils and a second arrangement of coils, the first coils having a at least two first windings and the second coil having at least a second windings, the second winding being juxtaposed intermediate the first windings, the method comprising the steps of:

energizing the first coil;

energizing the second coil; and

wherein the first and the second coil are alternately switched.

25. The method as claimed in claim 24, wherein the first winding and then the second winding are sequentially energized.

26. The method as claimed in claim 24, wherein when the first coil is energized, the second coil is open circuited.

27. The method as claimed in claim 24, wherein when the second coil is energized, the first coil is open circuited.

28. The method as claimed in claim 24, wherein the arrangement of coils is replicated and overlapped to create a larger arrangement of switched coils and/or where each coil is sequentially switched.

29. The method as claimed in claim 24, further comprising the step of providing a first and/or second coil comprising a single layer of parallel spaced conductors for two dimensional operations.

30. The method as claimed in claim 24, further comprising the step of providing a first and/or second coil comprising a first layer of parallel spaced conductors and a second parallel layer of orthogonally oriented parallel spaced conductors for three dimensional operations.

31. The method as claimed in claim 24, further comprising the step of arranging the first and second coils in a manner to enable fields to be produced in any one or any combination of X, Y and Z directions.

32. The method as claimed in claim 24, wherein the energizing is adapted to power a remote device.

33. The method as claimed in claim 24, wherein the energizing is adapted to communicate with a remote device.

34. The method as claimed in claim 33, wherein the remote device is a RFID device.

35. An interrogator adapted to energize an arrangement of coils, comprising:

processor means adapted to operate in accordance with a predetermined instruction set and being adapted to perform the method as claimed in claim 24.

36. A computer program product including;

a computer usable medium having computer readable program code and computer readable system code embodied on a medium for energizing at least two coils associated with interrogator apparatus in conjunction with commands from a data processing system, said computer program product including;

computer readable code within said computer usable medium for performing the method as claimed in claim 24.

37-38. -38. (canceled)