Adaptive control for improved RFID transponder read and write performance

• US 7,936,252 B2
• Filed: 12/07/2005
• Issued: 05/03/2011
• Est. Priority Date: 12/07/2005
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: ZIH Corp. (Zebra Technologies Corporation)
• Inventors: Donato, Daniel F.
• Primary Examiner(s): Zimmerman; Brian A
• Assistant Examiner(s): Syed; Nabil H
• Application Number:
  US11/297,164
• Publication Number:
  US 20070126558A1
• Time in Patent Office: 1,973 Days
• Field of Search: 340/10.1, 340/10.2, 340/10.51, 340/10.5, 340/572.1, 455/41.2, 455/63.1, 455/67.13
• US Class Current: 340/10.51
• CPC Class Codes: G06K 17/0025 the arrangement consisting of a wireless interrogation device in combination with a device for optically marking the record carrier
• 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

Abstract

System, methods and computer program product are provided for an adaptive control for adjusting the electromagnetic interrogation signal of an RFID transceiver where said signal is used to read and/or write to an RFID transponder, or to adjust the gain of the RFID transceiver, or adjust both the gain and the signal strength. The system includes a RFID transceiver having at least a transmitter portion and a receiver portion and capable of generating electromagnetic signals, a signal-to-noise ratio module, and an adaptive control module that adjusts the power of the electromagnetic signal of the transmitter portion or the gain of the receiver portion according to the signal-to-noise ratio of a first electromagnetic signal. In one embodiment the system may be employed in printer-encoder devices for reading or encoding RFID transponders during a printing process.

Claims

1. A system for communicating with an RFID transponder comprised of:

a transceiver having at least a receiver portion and a transmitter portion, wherein said receiver portion has an adjustable gain capable of varying amplification of a signal detected by said receiver portion, wherein and said transmitter portion has an adjustable strength electromagnetic interrogation signal used to encode information into or read information from said RFID transponder;

a signal-to-noise ratio module in communication with said transceiver, wherein said signal-to-noise ratio module determines a signal-to-noise ratio of a signal received by said receiver portion of said transceiver; and

an adaptive control module in communication with said signal-to-noise ratio module and said transmitter portion and said receiver portion of said transceiver,

wherein based upon said signal-to-noise ratio, said adaptive control module;

adjusts a signal strength of said electromagnetic interrogation signal of said transmitter portion of said transceiver, or

adjusts said gain of said receiver portion of said transceiver, or

adjusts both said signal strength of said electromagnetic interrogation signal of said transmitter portion of said transceiver and said gain of said receiver portion of said transceiver, and

wherein said system encodes said RFID transponder that originated said signal used to determine said signal-to-noise ratio.

2. The system of claim 1, wherein said receiver portion of said transceiver includes a low noise amplifier having an adjustable gain.

3. The system of claim 1, wherein said system comprises a portion of an RFID printer-encoder.

4. A system for communicating with an RFID transponder comprised of:

a transceiver having at least a transmitter portion that has an adjustable strength electromagnetic interrogation signal used to encode information into or read information from said RFID transponder;

a signal-to-noise ratio module in communication with said RFID transceiver, wherein said signal-to-noise ratio module determines a signal-to-noise ratio of a signal received by said transceiver; and

an adaptive control module in communication with said signal-to-noise ratio module and said transceiver,

wherein based upon said signal-to-noise ratio, said adaptive control module adjusts a signal strength of said electromagnetic interrogation signal used to encode information into or read information from said RFID transponder, and

wherein said system encodes or reads said RFID transponder that originated said signal used to determine said signal-to-noise ratio.

5. The system of claim 4, wherein said system comprises a portion of an RFID printer-encoder.

6. A system for communicating with an RFID transponder comprised of:

a transceiver having at least a receiver portion that has an adjustable gain that is used to receive a signal from said RFID transponder;

a signal-to-noise ratio module in communication with said RFID transceiver, wherein said signal-to-noise ratio module determines a signal-to-noise ratio of a signal received by said receiver portion of said transceiver; and

an adaptive control module in communication with said signal-to-noise ratio module and said transceiver,

wherein based upon said signal-to-noise ratio, said adaptive control module adjusts a gain of said receiver portion of said transceiver to facilitate reading information from said RFID transponder, and

wherein said system encodes said RFID transponder that originated said signal used to determine said signal-to-noise ratio.

7. The system of claim 6, wherein said receiver portion of said transceiver includes a low noise amplifier having an adjustable gain.

8. The system of claim 6, wherein said system comprises a portion of an RFID printer-encoder.

9. A method of communicating with an RFID transponder comprising:

exposing said RFID transponder to a first electromagnetic signal from a transmitter portion of a transceiver;

receiving with a receiver portion of said transceiver a response signal from said RFID transponder that is in response to said first electromagnetic signal;

determining a signal-to-noise ratio of said response signal;

adjusting signal strength of said transmitter portion of said transceiver, wherein said signal strength is determined by said signal-to-noise ratio of said response signal, or

adjusting gain of said receiver portion of said transceiver, wherein said gain is determined by said signal-to-noise ratio of said response signal, or

adjusting both signal strength of said transmitter portion of said transceiver and gain of said receiver portion of said transceiver, wherein said signal strength and said gain is determined by said signal-to-noise ratio of said response signal; and

subsequent to adjusting said signal strength, or said gain, or both said signal strength and said gain, encoding said RFID transponder from which said response signal was received.

10. The method of claim 9, further comprising interrogating said RFID transponder with a second electromagnetic signal from said transmitter portion of said transceiver for the purpose of reading said RFID transponder, wherein said second interrogation signal'"'"'s strength has been adjusted by the signal-to-noise ratio of said response signal.

11. A method of communicating with an RFID transponder comprising:

interrogating an RFID transponder with a first electromagnetic signal from a transmitter portion of a transceiver;

receiving a response signal from said RFID transponder that is in response to a first electromagnetic signal;

determining a signal-to-noise ratio of said response signal;

adjusting signal strength of said transmitter portion of said transceiver as said signal strength is determined by said signal-to-noise ratio of said response signal; and

subsequent to adjusting of said signal strength, encoding said RFID transponder from which said response signal was received.

12. The method of claim 11, further comprising interrogating said transponder with a second electromagnetic signal from said transmitter portion of said transceiver for the purpose of reading said RFID transponder, wherein said second electromagnetic signal'"'"'s strength has been adjusted by said signal-to-noise ratio of said response signal.

13. A method of communicating with an RFID transponder comprising:

interrogating an RFID transponder with a first electromagnetic signal from a transmitter portion of a transceiver;

receiving a response signal from said RFID transponder that is in response to said first electromagnetic signal with a receiver portion of said transceiver;

determining said signal-to-noise ratio of said response signal;

adjusting gain of said receiver portion of said transceiver, wherein said gain is determined by said signal-to-noise ratio of said response signal; and

subsequent to adjusting said gain, encoding said RFID transponder from which said response signal was received.

14. A computer program product comprised of code that is executable by a processor of a computing device for controlling a receiver portion and a transmitter portion of a transceiver for communicating with an RFID transponder, said computer program product comprising:

a first executable portion operating on said processor that determines a signal-to-noise ratio of a first electromagnetic signal received by the receiving portion of said transceiver;

a second executable portion operating on said processor that, based on said signal-to-noise ratio of said first electromagnetic signal, performs one or more of;

adjusting signal strength of said transmitter portion of said transceiver such that a second electromagnetic signal,. sent from said transmitter portion of said transceiver to said RFID transponder, is adjusted to compensate for noise as determined by said signal-to-noise ratio, and

adjusting gain of said receiver portion of said transceiver to compensate for said noise as determined by said signal-to-noise ratio; and

a third executable portion operating on said processor for encoding said RFID transponder that originated said first electromagnetic signal used to determine said signal-to -noise ratio.

15. A computer-readable storage medium containing a set of instructions for a computing device for controlling a receiver portion and a transmitter portion of a transceiver for communicating with an RFID transponder, the set of instructions comprising:

a first executable portion operating on a signal-to-noise ratio module for determining a signal-to-noise ratio of a first electromagnetic signal received by said receiving portion of said transceiver;

a second executable portion operating on an adaptive control module that, based on said signal-to-noise ratio of said first electromagnetic signal, performs one or more of;

adjusting signal strength of said transmitter portion of said transceiver such that a second electromagnetic signal sent from said transmitter portion of said transceiver to said RFID transponder is adjusted to compensate for noise as determined by said signal-to-noise ratio, and

adjusting the gain of said receiver portion of said transceiver to compensate for said noise as determined by said signal-to-noise ratio; and

a third executable portion for encoding said RFID transponder that originated said first electromagnetic signal used to determine said signal-to-noise ratio.