RFID system with an eddy current trap

• US 9,614,285 B2
• Filed: 02/19/2016
• Issued: 04/04/2017
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Blumberg, Jr., David
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US15/048,570
• Publication Number:
  US 20160172759A1
• Time in Patent Office: 410 Days
• Field of Search: 343741, 343742, 343753, 343850, 343860, 343866, 343867
• 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 RFID antenna assembly configured to be energized with a carrier signal is disclosed. The RFID 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. 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.

2. The RFID antenna assembly of claim 1 wherein the inductive component is configured to be positioned proximate an access assembly and to allow RFID-based actuation of the access assembly.

3. The RFID antenna assembly of claim 1 wherein at least one of the first phase shift element and the second phase shift element includes a capacitive component.

4. The RFID antenna assembly of claim 1 wherein the length of each antenna segment is approximately 10% of the wavelength of the carrier signal.

5. The RFID antenna assembly of claim 1 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.

6. The RFID antenna assembly of claim 5 wherein the first matching component includes a capacitive component.

7. The RFID antenna assembly of claim 5 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.

8. The RFID antenna assembly of claim 7 wherein the second matching component

includes a capacitive component.

9. 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, and 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;

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

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

10. The RFID antenna assembly of claim 9 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

11. The RFID antenna assembly of claim 9 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.

12. The RFID antenna assembly of claim 11 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.

13. 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 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;

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

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

14. The RFID antenna assembly of claim 13 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

15. The RFID antenna assembly of claim 13 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.

16. The RFID antenna assembly of claim 13 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.