HIGH-Q AND OVER-COUPLED NEAR-FIELD RFID READER ANTENNA FOR IMPROVED TAG READ RANGE

Number: 20170124790
Published: 2017-05-04
Filed: 2015-10-31
Assignee: DISNEY ENTERPRISES, INC.
Inventors: SAMPLE; ALANSON
CPC: G07C9/00309; G06K7/10148; G06K19/0723; G06K7/10415; G06K19/07762; G07C9/28; G06K7/10366
Verdict: Low Hardware
Source: Google Patents · FreePatentsOnline

The keeper's note

An RFID reader antenna design using impedance matching to improve tag read range via an over-coupled near-field configuration (PGPUB duplicate).

Abstract

An RFID system in which at least one of the RFID tag antenna and the RFID reader antenna has an impedance matching network associated therewith in order to better match the impedances of the two antennas. This impedance matching places the antennas into an over-coupled regime once they are within a reasonable distance of each other (e.g., 2 to 50 mm). It also increases the Q-factor of theimproved antenna, which can greatly increase the range at which the RFID reader can read the RFID tag. This improved RFID system may be used in any of a variety of application, including operating a door lock mechanism.

Background

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an RFID system.

FIG. 2 is a block diagram of a first embodiment of selected components of an RFID system.

FIG. 3 is a block diagram of a second embodiment of selected components of an RFID system.

FIG. 4 is a block diagram of a third embodiment of selected components ofan RFID system.

FIG. 5 is a schematic view of an antenna and impedance matching network of an RFID reader of the RFID system of FIG. 1.

FIG. 6 is schematic view of an antenna and impedance matching network of an RFID tag of the RFID system of FIG. 1.

FIG. 7 is a simplified illustration of a door with a door lock and latch mechanism, from agenerally horizontally-oriented view.

FIG. 8 is a simplified illustration of the door with the door lock and latch mechanism of FIG. 7, from a generally vertically-oriented view.

FIG. 9 is a simplified illustration of a wristband worn by a user, the wristband containing an RFID tag.DETAILED DESCRIPTION

While the embodiments disclosed herein are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail.It should be understood, however, that it is not intended to limit the invention to the particular form disclosed, but rather, the invention is to cover all modifications, equivalents, and alternatives of embodiments of the invention as defin

Claims

1. An RFID system, comprising: a tag including an antenna that selectively transfers a data signal; and a reader including an antenna that receives the data signal from the tag; wherein at least one of the tag antenna and the reader antenna have a Q-factor that is greater than 30; wherein the tag antenna and the reader antenna are sufficiently matched in impedance to place the two antennas into an over-coupled regime. 15. An RFID system, comprising: a tag including an antenna that selectively transfers a data signal; and a reader including an antenna that receives the data signal from the tag; wherein the tag antenna and the reader antenna are over-coupled when the antennas are within 10 mm of each other. 16. An RFID system, comprising: a tag including an antenna that selectively transfers a data signal, wherein the data signal includesa tag identifier; and a reader including an antenna that receives the data signal from the tag; wherein at least one of the tag antenna and the reader antenna have a Q-factor thatis greater than 30; wherein at least one of the tag antenna and the reader antenna include an impedance matching network associated therewith; wherein the tag antenna and the reader antenna are over-coupled when the antennas are within 10 mm of each other.