Tag antenna structure for wireless identification and wireless identification system using the tag antenna structure

• US 8,104,691 B2
• Filed: 10/31/2007
• Issued: 01/31/2012
• Est. Priority Date: 10/31/2006
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Sim, Dong-Uk, Choi, Hyung-Do, Choi, Jae-Ick, Kim, Dongho
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): GUDORF, LAURA A
• Application Number:
  US12/447,569
• Publication Number:
  US 20100001080A1
• Time in Patent Office: 1,553 Days
• Field of Search: 235/492, 235/375, 235/487, 343/700, 343/795
• US Class Current: 235/492
• 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 15/006 Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
• CPC Class Codes: H01Q 15/008 said selective devices having Sievenpipers' mushroom elements
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

Provided are a tag antenna for wireless identification and a wireless identification system including the tag antenna. The tag antenna includes: a substrate formed of a first dielectric; a conductive ground layer formed underneath the substrate; an AMC layer formed on the substrate; and a wireless identification chip adhered onto the AMC layer.

Claims

1. A tag antenna structure for wireless identification, comprising:

a substrate formed of a first dielectric;

a conductive ground layer formed underneath the substrate;

an artificial magnetic conductor (AMC) layer formed on the substrate; and

a tag antenna including a wireless identification chip adhered to the AMC layer, wherein the tag antenna structure is free of vias between the AMC layer and the conductive ground layer.

2. The tag antenna structure of claim 1, wherein the tag antenna is mounted on a conductor.

3. The tag antenna structure of claim 1, wherein the tag antenna structure has a low-profile structure.

4. The tag antenna structure of claim 1, wherein the AMC layer comprises patterns in which conductive unit cells having predetermined shapes are arrayed at regular distances.

5. The tag antenna structure of claim 4, wherein the AMC layer comprises unit cells which have square patch shapes and are arrayed at predetermined distances.

6. The tag antenna structure of claim 5, wherein the AMC layer comprises four unit cells which are disposed in checkered patterns on the substrate.

7. The tag antenna structure of claim 5, wherein a frequency and an identification distance of the tag antenna vary according to variations of a length of a side of each of the unit cells.

8. The tag antenna structure of claim 4, wherein the wireless identification chip operates by energy of received electromagnetic waves.

9. The tag antenna structure of claim 8, wherein the tag antenna comprises two conductive plates connected to each other through a connector, and the wireless identification chip is disposed in the connector.

10. The tag antenna structure of claim 9, wherein ends of the connector are inserted into the two conductive plates to connect the two conductive plates so as to form concave portions, and slots are formed in the concave portions.

11. The tag antenna structure of claim 1, wherein the tag antenna has a distance of ¼

or less of a wavelength of transmitted and received electromagnetic waves from the conductive ground layer and is adhered to the AMC layer.

12. The tag antenna structure of claim 1, wherein a second dielectric layer is formed on the AMC layer, wherein the tag antenna is mounted on the second dielectric layer.

13. The tag antenna structure of claim 1, wherein a surface of the AMC layer has a HIS (High Impedance Surface) characteristic.

14. The tag antenna structure of claim 1, wherein the substrate is formed of epoxy.

15. A wireless identification system, comprising a tag antenna structure, the tag antenna structure including;

a substrate formed of a first dielectric;

a conductive ground layer formed underneath the substrate;

an artificial magnetic conductor (AMC) layer formed on the substrate; and

a tag antenna including a wireless identification chip adhered to the AMC layer, wherein the tag antenna structure is free of vias between the AMC layer and the conductive ground layer.

16. The wireless identification system of claim 15, wherein the tag antenna structure has a low-profile structure and is directly mounted on a conductor.

17. The wireless identification system of claim 16, wherein the AMC layer comprises unit cells which have square patch shapes and are arrayed at the predetermined distances.

18. The wireless identification system of claim 16, wherein the wireless identification chip operates by energy of received electromagnetic waves, and the tag antenna comprises the conductive plates which have square patch shapes and are connected to each other through the connector, wherein the wireless identification chip is disposed in the connector.

19. The wireless identification system of claim 16, wherein the wireless identification system is an RFID (radio frequency identification) system.

20. A tag antenna structure for wireless identification, comprising:

a substrate formed of a first dielectric;

a conductive ground layer formed underneath the substrate;

an artificial magnetic conductor (AMC) layer formed on the substrate; and

a tag antenna including;

a wireless identification chip adhered to the AMC layer,

two conductive plates connected to each other through a connector, the wireless identification chip being disposed in the connector.