RFID antenna system and method

• US 9,300,032 B2
• Filed: 10/31/2007
• Issued: 03/29/2016
• Est. Priority Date: 10/31/2007
• Status: Expired due to Fees

• Current Assignee: Sensormatic Electronics LLC (Johnson Controls International plc)
• Original Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Inventors: Day, Edward
• Primary Examiner(s): Backer, Firmin
• Assistant Examiner(s): TUN, NAY L
• Application Number:
  US11/930,817
• Publication Number:
  US 20090108996A1
• Time in Patent Office: 3,072 Days
• Field of Search: 3405721-5727, 340/825.54, 340/568.1
• US Class Current: 1/1
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• 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 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

The present invention provides an RFID device having a substrate body, and an IC component and antenna disposed thereon. The RFID device may further include one or more spacing elements, wherein at least a portion of the substrate body is adapted to be disposed around at least a portion the spacing element, thus reducing the overall size of the substrate body with proper impedance matching. The RFID device may further include an EAS element coupled to the substrate body and/or the spacing element in order to create a combination RFID/EAS device with the ability to reduce its overall footprint without sacrificing the ability to provide both identification and article surveillance functions.

Claims

1. A radio frequency identification (RFID)/electronic article surveillance (EAS) device, the device comprising:

a spacing element comprising a planar body with a predetermined thickness and formed of a dielectric material to define first and second major faces which are opposed to each other, the planar body having an EAS element embedded therein;

a dielectric substrate body distinct from the spacing element, the dielectric substrate body defining an elongated length which includes a first surface and a second surface comprising opposing major sides of the dielectric substrate body;

an RFID integrated circuit disposed on the dielectric substrate body;

a dipole antenna disposed on the dielectric substrate body, the dipole antenna comprised of a first conductive element and a second conductive element, each electrically connected to the RFID integrated circuit, and each respectively extending away from the RFID integrated circuit along said elongated length of the dielectric substrate body in first and second opposing directions;

each of the first and second conductive elements respectively comprise an inner length proximal to the RFID integrated circuit, and an outer length spaced apart from the RFID integrated circuit a greater distance along the elongated length as compared to the inner length;

the elongated length of the dielectric substrate body is wrapped around at least a portion of the spacing element so that first surface is in contact with both the first and second faces of the spacing element; and

wherein the dielectric substrate body is positioned so that the RFID integrated circuit and the inner length of each of the first and second conductive elements are adjacent to the first major face of the spacing element, and the outer length of each of the first and second conductive elements are disposed adjacent to the second major face of the spacing element.

2. The device according to claim 1, wherein the first and second conductive elements which form the dipole antenna are each respectively comprised of an electrically conductive material patterned on a surface of the dielectric substrate body.

3. The device according to claim 2, wherein the electrically conductive material pattern includes at least one of a plurality of polygons and a meanderline.

4. The device according to claim 3, wherein each of the plurality of polygons has a substantially rectangular shape.

5. The device according to claim 4, wherein each of the plurality of polygons is non-continuous to thereby provide a single electrically conductive path.

6. The device according to claim 1, wherein the spacing element is comprised of first and second spacing element portions and wherein the EAS element is disposed between the first and second spacing element portions.

7. The device according to claim 1, wherein the EAS element is an acousto-magnetic device.

8. The device according to claim 1, wherein the EAS element is a microwave device.

9. The device according to claim 1, wherein the dielectric substrate body is constructed from a material including at least one of polyimide, polyester, fiberglass, ceramic, plastic, and paper.

10. The device according to claim 1, wherein the each of the first and second conductive elements which comprise the dipole antenna are constructed from a material including at least one of copper, aluminum and conductive ink.

11. A combination radio frequency identification (RFID)/electronic article surveillance (EAS) device, the device comprising:

a spacing element formed of first and second spacing element portions, the spacing element comprising a body with a predetermined thickness and formed of a dielectric material to define first and second major faces which are opposed to each other;

an EAS element disposed within the spacing element in contact with the first and second spacing element portions;

a dielectric substrate body distinct from the spacing element, the dielectric substrate body defining an elongated length which includes a first surface and a second surface comprising opposing major sides of the dielectric substrate body;

an RFID integrated circuit disposed on the dielectric substrate body;

a dipole antenna disposed on the dielectric substrate body, the dipole antenna comprised of a first conductive element and a second conductive element, each electrically connected to the RFID integrated circuit, and each respectively extending away from the RFID integrated circuit along said elongated length of the dielectric substrate body in first and second opposing directions;

each of the first and second conductive elements respectively comprise an inner length proximal to the RFID integrated circuit, and an outer length distal from the RFID integrated circuit;

the dielectric substrate body wrapped around the exterior of the spacing element so that the first surface is in contact with the first and second faces of the spacing element; and

wherein the dielectric substrate body is positioned so that the RFID integrated circuit and the inner length of each of the first and second conductive elements are adjacent to the first major face of the spacing element, and the outer length of each of the first and second conductive elements are disposed adjacent to the second major face of the spacing element.

12. The RFID/EAS device according to claim 11, wherein the first and second conductive elements which comprise the dipole antenna are each respectively formed of an electrically conductive material pattern on the first surface of the dielectric substrate body.

13. The RFID/EAS device according to claim 12, wherein the electrically conductive material pattern includes at least one of a plurality of polygons and a meanderline.

14. The RFID/EAS device according to claim 13, wherein each of the plurality of polygons has a substantially rectangular shape.

15. The RFID/EAS device according to claim 13, wherein each of the plurality of polygons is non-continuous to thereby provide a single electrically conductive path.

16. The RFID/EAS device according to claim 11, wherein the EAS element is disposed between the first and second spacing element portions.

17. The RFID/EAS device according to claim 11, further comprising a third conductive element which forms an electrical connection between the RFID integrated circuit and each of the first and second conductive elements to form a current loop.

18. A method of assembling a radio frequency identification device (RFID)/electronic article surveillance (EAS) device, comprising the steps of:

providing a spacing element by positioning an EAS element between a first dielectric spacing element portion and a second dielectric spacing element portion to form a stack which defines a planar body having a first and second major face which are opposed;

disposing on a planar dielectric substrate body a dipole antenna and an RFID integrated circuit;

arranging a first conductive element and a second conductive element which comprise the dipole antenna respectively so that each is electrically connected to the RFID integrated circuit at a first end thereof and each extends away from the RFID integrated circuit along an elongated length of the planar dielectric substrate body in first and second opposing directions to a second end;

wrapping the elongated length of the planar dielectric substrate body around an exterior of the spacing element so that a first major surface of the planar dielectric substrate body is in contact with the first and second major faces of the spacing element; and

positioning the planar dielectric substrate body relative to the spacing element so that the RFID integrated circuit and an inner length of each of the first and second conductive elements proximate to the first end is adjacent to the first major face of the spacing element, and an outer length of each of the first and second conductive elements proximate to the second end are disposed adjacent to the second major face of the spacing element.