RFID system

• US 8,610,577 B2
• Filed: 05/20/2009
• Issued: 12/17/2013
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Blumberg, David Jr.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US12/469,562
• Publication Number:
  US 20090289796A1
• Time in Patent Office: 1,672 Days
• Field of Search: 340/572.1, 340/572.7, 340/572.8, 340/10.1, 455/41.1, 343/741, 343/866
• US Class Current: 340/572.7
• 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 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• 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
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A magnetic field focusing assembly includes a magnetic field generating device configured to generate a magnetic field, and a split ring resonator assembly configured to be magnetically coupled to the magnetic field generating device and configured to focus the magnetic field produced by the magnetic field generating device.

Claims

1. 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 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; and

at least one capacitive component coupled to the inductive component.

2. The RFID antenna assembly of claim 1 wherein the circumference of the loop antenna assembly is approximately 10% of the wavelength of the carrier signal.

3. The RFID antenna assembly of claim 1 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.

4. The RFID antenna assembly of claim 3 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.