Adaptive control for improved RFID transponder read and write performance

• US 20070126558A1
• Filed: 12/07/2005
• Published: 06/07/2007
• Est. Priority Date: 12/07/2005
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: ZIH Corp. (Zebra Technologies Corporation)
• Inventors: Donato, Daniel
• Granted Patent: US 7,936,252 B2
• Time in Patent Office: Days
• US Class Current: 340/10.510
• 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:

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

a signal-to-noise ratio module in communication with said RFID transceiver, wherein said signal-to-noise ratio module determines the signal-to-noise ratio of a signal received by the receiver portion of the RFID 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 the strength of said electromagnetic interrogation signal of said transmitter portion of said transceiver or adjusts the gain of the receiver portion of the transceiver, or adjusts both the strength of said electromagnetic interrogation signal of said transmitter portion of said transceiver and said gain of the receiver portion of the transceiver.

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:

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

a signal-to-noise ratio module in communication with said RFID transceiver, wherein said signal-to-noise ratio module determines the signal-to-noise ratio of a signal received by the RFID 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 the strength of said electromagnetic interrogation signal this is used to encode information into or read information from the RFID transponder.

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:

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

a signal-to-noise ratio module in communication with said RFID transceiver, wherein said signal-to-noise ratio module determines the signal-to-noise ratio of a signal received by the receiver portion of the RFID 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 the gain of the receiver portion of said transceiver to facilitate reading information from the RFID transponder.

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 the steps of:

exposing one or more RFID transponders to a first electromagnetic signal from a transmitter portion of a transceiver;

receiving with a receiver portion of the transceiver a response signal from at least one of said one or more RFID transponders that is in response to said first electromagnetic signal;

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

adjusting signal strength of said transmitter portion of said transceiver as said signal strength is determined by the signal-to-noise ratio of said response signal or adjusting gain of the receiver portion of said transceiver as said gain is determined by the signal-to-noise ratio of said response signal, or adjusting both signal strength of said transmitter portion of said transceiver and gain of the receiver portion of said transceiver as said signal strength and said gain is determined by the signal-to-noise ratio of said response signal.

10. The method of claim 9, further comprising the step of interrogating at least one of said one or more RFID transponders with a second electromagnetic signal from said transmitter portion of said transceiver for the purpose of reading or encoding said one or more RFID transponders, 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 the steps of:

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;

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

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

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

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

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 the transceiver;

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

adjusting gain of said receiver portion of said transceiver as said gain is determined by the signal-to-noise ratio of said response signal.

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 an RFID transceiver for communicating with an RFID transponder, said computer program product comprising:

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

a second executable portion operating on said processor that based on the signal-to-noise ratio of the first electromagnetic signal performs one or more of adjusting signal strength of the transmitter portion of the transceiver such that a second electromagnetic signal from said transmitter portion of said transceiver to said RFID transponder is adjusted to compensate for noise as determined by the signal-to-noise ratio and adjusts the gain of the receiver portion of the transceiver to compensate for noise as determined by the 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 an RFID transceiver for communicating with an RFID transponder, the set of instructions comprising:

a signal-to-noise ratio module for determining the signal-to-noise ratio of a first electromagnetic signal received by the receiving portion of a transceiver; and

an adaptive control module that based on the signal-to-noise ratio of the first electromagnetic signal performs one or more of adjusting signal strength of the transmitter portion of the transceiver such that a second electromagnetic signal from said transmitter portion of said transceiver to said RFID transponder is adjusted to compensate for noise as determined by the signal-to-noise ratio and adjusts the gain of the receiver portion of the transceiver to compensate for noise as determined by the signal-to-noise ratio.