Automatic tuning reader

• US 8,219,053 B2
• Filed: 10/20/2008
• Issued: 07/10/2012
• Est. Priority Date: 10/19/2007
• Status: Expired due to Fees

• Current Assignee: Destron Fearing Corporation (Merck & Co., Inc.)
• Original Assignee: Destron Fearing Corporation (Merck & Co., Inc.)
• Inventors: Mejia, Ezequiel, Smirnov, Yuri
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Sorawat, Stacey
• Application Number:
  US12/254,241
• Publication Number:
  US 20090102607A1
• Time in Patent Office: 1,359 Days
• Field of Search: 455/62, 455 631- 65, 455/69, 455/114.1, 455/115.1, 455121-123
• US Class Current: 455/193.1
• 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: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A system and method of automatically tuning a reading device that remotely monitors RFID tags or transponders. The reading device utilizes the phase signal of an antenna signal wherein the harmonic of the antenna signal is filtered through a signal coupling transformer and utilizes the antenna current reading to determine the optimal capacitance setting for the reader by adjusting capacitors and storing the relative phase signal and level of current in a processor. In one embodiment, the method comprises supplying power to the reading device, monitoring the power supply, storing data related to the monitored power supply, emitting a signal from an antenna, filtering the harmonic of such signal, outputting the phase signal to a processor and adjusting capacitors based on the phase signal and monitored current.

Claims

1. An automatic tuning reading device for communicating with a receiver comprising:

a current monitor for monitoring the current received from a power supply of the reading device;

an antenna driver;

one or more capacitors in communication with the antenna driver;

one or more switches for controlling the one or more capacitors;

a processor with a memory component;

an antenna in communication with the one or more capacitors via a transmission path; and

3

a signal coupling transformer;

wherein the capacitors are adjusted along the transmission path and the signal coupling transformer extracts the harmonic level of an antenna signal retrieved from the antenna, outputs the phase signal of the extracted harmonic level to the processor and the processor stores data related to such phase signal and data related to the monitored current in said memory and sends a signal to the one or more switches to adjust the one or more capacitors to automatically tune the antenna based on the stored data.

2. The reading device of claim 1 further comprising a display component.

3. The reading device of claim 1 wherein the processor sends a signal to the one or more switches to circle through multiple capacitor combinations before sending a signal to adjust the one or more capacitors to automatically tune the antenna.

4. The reading device of claim 1 further comprising an amplifier.

5. The reading device of claim 4 wherein the signal coupling transformer receives a signal from the antenna and outputs said received signal to the amplifier and the amplified signal is outputted to the processor.

6. The reading device of claim 1 wherein the signal coupling transformer is tuned between 280 and 500 KHz.

7. The reading device of claim 1 wherein the harmonic that is extracted by the signal coupling transformer is at or near the 3rd harmonic.

8. The reading device of claim 1 wherein the signal coupling transformer has a high Q factor.

9. The reading device of claim 8 wherein the antenna has a high Q factor.

13. The reading device of claim 1 wherein the harmonic that is extracted by the signal coupling transformer is at or near the 4th harmonic.

14. The reading device of claim 1 wherein the harmonic that is extracted by the signal coupling transformer is at or near the 5th harmonic.

10. A method of automatically tuning a reading device having an antenna and a processor comprising:

supplying power to the reading device;

monitoring the power supply;

storing data related to the monitored power supply in a memory component of the processor;

emitting a signal from the antenna;

receiving the antenna signal in a signal coupling transformer;

extracting a harmonic of the antenna signal in the signal coupling transformer;

outputting the phase signal of the extracted harmonic to the processor;

storing data related to the phase signal in a memory component of the processor;

adjusting capacitors that are in communication with the antenna via a transmission path; and

tuning the antenna to an optimal setting based on the data stored in the processor.

11. The method of claim 10 further comprising:

receiving a harmonic signal from the antenna;

amplifying the signal received from the antenna;

outputting the amplified signal to the processor;

generating a display on the reading device indicative of the signal received from the antenna.

12. The method of claim 10 wherein the harmonic is at or near the third harmonic.

15. The method of claim 10 wherein the harmonic is at or near the fourth harmonic.

16. The method of claim 10 wherein the harmonic is at or near the fifth harmonic.