RFID TAG WITH ANTENNA AND SENSE CONDUCTOR

Abstract

A radio frequency identification (RFID) system and more particularly a tag comprising a transponder forming parts of such a system. The tag preferably includes a substrate; a transponder mounted on the substrate; the transponder comprising electronic circuitry and an antenna connected to the circuitry; a sense element on the substrate which is sensitive to damage to the substrate and which is connected to a sense input of the circuitry; the antenna comprising a metal layer and the sense element a layer of conductive ink.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS

The invention will now further be described, by way of example only, with reference to the accompanying diagrams wherein:

FIG. 1 is a basic block diagram of a radio frequency identification system comprising at least one tag according to the invention;

FIG. 2 is a plan view of the tag according to the invention; and

FIG. 3 is an exploded perspective view of the tag according to the invention.

Claims

1. A tag for a radio frequency identification system, the tag comprising: a substrate;a transponder mounted on the substrate;the transponder comprising electronic circuitry and an antenna connected to the circuitry;a sense element on the substrate which is sensitive to damage to the substrate and which element is connected to a sense input of the circuitry;the antenna comprising a metal layer and the sense element a layer of conductive ink.

2. A tag as claimed in claim 1 wherein the sense element comprises a loop.

3. A tag as claimed in claim 1 wherein the circuitry is integrated on a single chip.

4. A tag as claimed in claim 1 wherein the circuitry comprises a controller sensitive to whether the sense element is in a first low resistance state or in a second higher resistance state and operative to generate a first string of data when the element is in the first state and a second string of data when the element is in the second state.

5. A tag as claimed in claim 4 wherein the second string of data is the one's complement of the first string of data.

6. A tag as claimed in claim 1 wherein the antenna, chip and sense element are located in substantially the same plane.

7. A tag as claimed in claim 1 wherein the antenna is formed by a first process comprising one of a metal depositing, plating, etching or similar process.

8. A tag as claimed in claim 7 wherein the element is formed by a second process comprising a conductive ink printing process.

9. An RFID system comprising a reader and at least one tag as claimed in claim 1.

10. A method of forming an RFID tag, the method comprising the steps of: forming a conductive antenna for transponder circuitry on a substrate, utilizing a first process; andforming a sense element on the substrate that is sensitive to damage to the substrate, utilizing a second process.

11. A method as claimed in claim 10 wherein the first process is different from the second process.

12. A method as claimed in claim 11 wherein the first process comprises at least one of a metal depositing, plating, etching or similar process.

13. A method as claimed in claim 11 wherein the second process comprises a conductive ink printing process.