RFID SYSTEM WITH AN EDDY CURRENT TRAP

• US 20110205134A1
• Filed: 02/25/2011
• Published: 08/25/2011
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Blumberg, David JR.
• Granted Patent: US 9,270,010 B2
• Time in Patent Office: Days
• US Class Current: 343/753
• CPC Class Codes: A47J 31/40 Beverage-making apparatus with dispensing means for adding a measured quantity of ingredients, e.g. coffee, water, sugar, cocoa, milk, tea
• 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 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H01Q 19/00 Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic combination of horns with slotted waveguide array H01Q13/0233
• 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

An REID antenna assembly configured to be energized with a carrier signal is disclosed. The REID antenna assembly includes an inductive component including a loop antenna assembly, at least one capacitive component coupled to the inductive component, and an eddy current trap positioned a predetermined distance from the loop antenna assembly.

Claims

1. A magnetic field focusing assembly comprising:

a magnetic field generating device configured to generate a magnetic field;

a split ring resonator assembly configured to be magnetically coupled to the magnetic field generating device and configured to focus at least a portion of the magnetic field produced by the magnetic field generating device; and

an eddy current trap positioned a predetermined distance from the magnetic field generating device.

2. The magnetic field focusing assembly of claim 1 wherein the magnetic field generating device includes an antenna assembly.

3. The magnetic field focusing assembly of claim 1 wherein the split ring resonator assembly is constructed of a metamaterial.

4. The magnetic field focusing assembly of claim 1 wherein the split ring resonator assembly is constructed of a non-ferrous material.

5. The magnetic field focusing assembly of claim 1 wherein the split ring resonator assembly is configured to be generally planar and have a geometric shape.

6. The magnetic field focusing assembly of claim 1 wherein the magnetic field generating device is configured to be energized by a carrier signal having a defined frequency and the split ring resonator assembly is configured to have a resonant frequency that is approximately 5-10% higher than the defined frequency of the carrier signal.

7. The magnetic field focusing assembly of claim 1 wherein the magnetic field generating device is configured to be energized with a carrier signal, the magnetic field generating device including:

an inductive component including a loop antenna assembly, wherein the circumference of the loop antenna assembly is no more than 25% of the wavelength of the carrier signal; and

at least one capacitive component coupled to the inductive component.

8. The magnetic field focusing assembly of claim 7 wherein the inductive component is configured to be positioned proximate a first slot assembly to detect the presence of a first RFID tag assembly within the first slot assembly and not detect the presence of a second RFID tag assembly within a second slot assembly that is adjacent to the first slot assembly.

9. The magnetic field focusing assembly of claim 7 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

10. The magnetic field focusing assembly of claim 7 wherein the at least one capacitive component includes a first capacitive component configured to couple a port on which the carrier signal is received and a ground.

11. The magnetic field focusing assembly of claim 10 wherein the at least one capacitive component includes a second capacitive component configured to couple the port on which the carrier signal is received and the inductive component.

12. The magnetic field focusing assembly of claim 1 wherein the magnetic field generating device is configured to be energized with a carrier signal, the magnetic field generating device including:

an inductive component including a multi-segment loop antenna assembly, wherein the multi-segment loop antenna assembly includes;

at least a first antenna segment including at least a first phase shift element configured to reduce the phase shift of the carrier signal within the at least a first antenna segment, and

at least a second antenna segment including at least a second phase shift element configured to reduce the phase shift of the carrier signal within the at least a second antenna segment,

wherein the length of each antenna segment is no more than 25% of the wavelength of the carrier signal; and

at least one matching component configured to adjust the impedance of the multi-segment loop antenna assembly.

13. The magnetic field focusing assembly of claim 12 wherein the inductive component is configured to be positioned proximate an access assembly and to allow RFID-based actuation of the access assembly.

14. The magnetic field focusing assembly of claim 12 wherein at least one of the first phase shift element and the second phase shift element includes a capacitive component.

15. The magnetic field focusing assembly of claim 12 wherein the length of each antenna segment is approximately 10% of the wavelength of the carrier signal.

16. The magnetic field focusing assembly of claim 12 wherein the at least one matching component includes:

a first matching component configured to couple a port on which the carrier signal is received and a ground.

17. The magnetic field focusing assembly of claim 16 wherein the first matching component includes a capacitive component.

18. The magnetic field focusing assembly of claim 16 wherein the at east one matching component includes:

a second matching component configured to couple the port on which the carrier signal is received and the inductive component.

19. The magnetic field focusing assembly of claim 18 wherein the second matching component includes a capacitive component.

20. An RFID antenna assembly configured to be energized with a carrier signal, the RFID antenna assembly comprising:

an inductive component including a multi-segment loop antenna assembly, wherein the multi-segment loop antenna assembly includes;

at least a first antenna segment including at least a first phase shift element configured to reduce the phase shift of the carrier signal within the at least a first antenna segment, and

at least a second antenna segment including at least a second phase shift element configured to reduce the phase shift of the carrier signal within the at least a second antenna segment,

wherein the length of each antenna segment is no more than 25% of the wavelength of the carrier signal;

at least one matching component configured to adjust the impedance of the multi-segment loop antenna assembly; and

an eddy current trap positioned a predetermined distance from the multi-segment loop antenna assembly.

21. The RFID antenna assembly of claim 20 wherein the inductive component is configured to be positioned proximate an access assembly and to allow RFID-based actuation of the access assembly.

22. The RFID antenna assembly of claim 20 wherein at least one of the first phase shift element and the second phase shift element includes a capacitive component.

23. The RFID antenna assembly of claim 20 wherein the length of each antenna segment is approximately 10% of the wavelength of the carrier signal.

24. The RFID antenna assembly of claim 20 wherein the at least one matching component includes:

a first matching component configured to couple a port on which the carrier signal is received and a ground.

25. The RFID antenna assembly of claim 24 wherein the first matching component includes a capacitive component.

26. The RPM antenna assembly of claim 24 wherein the at least one matching component includes:

a second matching component configured to couple the port on which the carrier signal is received and the inductive component.

27. The RFID antenna assembly of claim 26 wherein the second matching component includes a capacitive component.

28. An RFID antenna assembly configured to be energized with a carrier signal, the RFID antenna assembly comprising:

an inductive component including a loop antenna assembly, wherein the circumference of the loop antenna assembly is no more than 25% of the wavelength of the carrier signal;

at least one capacitive component coupled to the inductive component; and

an eddy current trap positioned a predetermined distance from the loop antenna assembly.

29. The RFID antenna assembly of claim 28 wherein the inductive component is configured to be positioned proximate a first slot assembly to detect the presence of a first RFID tag assembly within the first slot assembly and not detect the presence of a second RFID tag assembly within a second slot assembly that is adjacent to the first slot assembly.

30. The RFID antenna assembly of claim 28 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

31. The RFID antenna assembly of claim 28 wherein the at least one capacitive component includes a first capacitive component configured to couple a port on which the carrier signal is received and a ground.

32. The RFID antenna assembly of claim 31 wherein the at least one capacitive component includes a second capacitive component configured to couple the port on which the carrier signal is received and the inductive component.

33. An RFID antenna assembly configured to be energized with a carrier signal, the RFID antenna assembly comprising:

an inductive component including a loop antenna assembly;

at least one capacitive component coupled to the inductive component; and

an eddy current trap positioned a predetermined distance from the loop antenna assembly.

34. The RFID antenna assembly of claim 33 wherein the inductive component is configured to be positioned proximate a first slot assembly to detect the presence of a first RFID tag assembly within the first slot assembly and not detect the presence of a second RFID tag assembly within a second slot assembly that is adjacent to the first slot assembly.

35. The RFID antenna assembly of claim 33 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

36. The RFID antenna assembly of claim 33 wherein the at least one capacitive component includes a first capacitive component configured to couple a port on which the carrier signal is received and a ground.

37. The RFID antenna assembly of claim 36 wherein the at least one capacitive component includes a second capacitive component configured to couple the port on which the carrier signal is received and the inductive component.