×

Radio frequency identification interrogator signal processing system for reading moving transponders

  • US 6,122,329 A
  • Filed: 09/15/1998
  • Issued: 09/19/2000
  • Est. Priority Date: 02/06/1998
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for recovering a backscattered data signal from a radio frequency (RF) transponder comprising the steps of:

  • receiving in-phase (I) and quadrature-phase (Q) signals from said RF transponder, said I and Q signals containing said backscattered data signal directly modulated onto an RF carrier wherein a phase angle P(t) between the I and Q signals and said RF carrier is substantially unknown;

    estimating said phase angle β

    (t) between the I and Q signals and said RF carrier; and

    recovering said backscattered data signal by combining said I and Q signals with said estimated phase angle β

    (t).

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×