×

Methods and apparatuses for RFID tag range determination

  • US 8,279,112 B2
  • Filed: 11/03/2009
  • Issued: 10/02/2012
  • Est. Priority Date: 11/03/2008
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of determining a position of an RFID tag, the method comprising:

  • broadcasting, by the tag reader, interrogation signals to the tag at a plurality of discrete frequencies;

    receiving, by the tag reader, returned signals from the tag in response to the interrogation signals;

    determining, by a phase-estimator, phase delays associated with the returned signals;

    producing, by a processor, a data set from the determined phase delays;

    selecting, by the processor, a function having a periodic characteristic which best fits the produced data set; and

    determining, by the processor, a distance between the RFID tag and the RFID tag reader based upon the selected function.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×