System and method for improving the detection efficiency of an identification system including a transponder and a reader

• US 20070046429A1
• Filed: 09/27/2005
• Published: 03/01/2007
• Est. Priority Date: 08/29/2005
• Status: Active Grant

• Current Assignee: Datamars SA (Province of Québec)
• Original Assignee: Datamars SA (Province of Québec)
• Inventors: Mutti, Carlo, Di Domenico, Mauro, Parvis, Hassan-Zade, Malacarne, Enrico
• Granted Patent: US 7,432,809 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: A01K 11/006 Automatic identification systems for animals, e.g. electronic devices, transponders for animals identification systems for access to feeding pens A01K1/0209; ear tags with electronic identification means A01K11/004
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device

Abstract

The invention relates to a radio frequency (RF) system and method for improving the detection efficiency of an identification system including a transponder and a reader.

The system (1) comprises an interrogator reader device (3) having an interrogator coil antenna (4) and a transponder (2) having a transponder coil antenna (5) and a microchip (6) Advantageously, the interrogator reader device (3) comprises a detection portion (11) including a sensitive signal gain detector (SSGN) for detecting just the presence of the transponder coil antenna (5) in case of misplacement of the transponder or broken link between the transponder coil antenna (5) and the microchip (6).

The invention allows remedying to those potentially dangerous situations that might lead to a misdetection of the transponder (2).

Claims

1. A radio frequency (RF) identification system (1) comprising an interrogating reader device (3) having an interrogator coil antenna (4) and a transponder (2) having a transponder coil antenna (5) and a microchip (6), characterized in that said interrogator reader device (3) comprises a detection portion (11) including a sensitive signal gain detector (SSGN) for detecting just the presence of said transponder coil antenna (5) in case of misplacement of the transponder or broken link between said transponder coil antenna (5) and said microchip (6).

2. A radio frequency (RF) identification system (1) according to claim 1, characterized in that said sensitive signal gain detector (SSGN) is a special circuit for detection.

3. A radio frequency (RF) identification system (1) according to claim 1, characterized in that said sensitive signal gain detector (SSGN) detects just a reduction in the power transfer efficiency between said transponder coil antenna (5) and said interrogator coil antenna (4) of the interrogator reader device (3).

4. A radio frequency (RF) identification system (1) according to claim 1, characterized in that one terminal of said interrogator antenna (4) is connected to a gain stage (12) of said detection portion (11) through a diode (15).

5. A radio frequency (RF) identification system (1) according to claim 4, characterized in that a de-coupling capacitance (14) is connected between said diode (14) and a voltage potential reference (GND).

6. A radio frequency (RF) identification system (1) according to claim 4, characterized in that the output of the gain stage (12) is connected to said sensitive signal gain detector (SSGN) to provide an output signal (20) that is indicative of the presence of a secondary coil (L2) of the transponder (2).

7. A radio frequency (RF) identification system (1) according to claim 4, characterized in that said interrogator reader device (3) is provided with a specific light emission device (18) or with a sound emitter (19) directly driven by the output of said signal gain detector (SSGN).

8. A radio frequency (RF) identification system (1) according to claim 4, characterized in that the light and/or sound provided by said light emission device (18) and/or sound emitter (19) are distinguished by the lights and/or sounds that said interrogating reader device (3) normally emits to indicate the presence of a recognized transponder (2) and/or the load of the information stored therein.

9. A method for improving the detection efficiency of a radio frequency (RF) identification system (1) comprising an interrogator reader device (3) having an interrogator coil antenna (4) and a transponder (2) having a transponder coil antenna (5) and a microchip (6), characterized by the following steps:

supplying one terminal of said interrogator coil antenna (4) with a periodic voltage value, thus obtaining a resonant primary coil (L1);

checking the possible presence of the transponder (2) bringing the inductive load represented by said transponder coil antenna (5) into the magnetic field of said primary coil (L1);

detecting just presence of said transponder coil antenna (5) through a detection portion (11) connected to the opposite terminal of said interrogator coil antenna (4) and including a sensitive signal gain detector (SSGN);

emitting a warning signal in case of misplacement of the transponder or broken link between said transponder coil antenna (5) and said microchip (6).

10. A method according to claim 9, characterized in that said warning signal is used to drive a specific light emission device (18) and/or a sound emitter (19) in said interrogator reader device (3).