Abstract: An object orientation-independent information storage and retrieval system ‘tags’ an object with a compact, strip-embedded transponder containing object identification information. The transponder remains unpowered until the tagged object passes through a pulsed time-varying magnetic field generated by a tag reader. In response to a transponder coil sensing this interrogation magnetic field, the transponder extracts and stores energy from the incident field, powering up the transponder and stimulating the emission of an alternating magnetic field reply burst encoded with information stored in memory. The reply burst has the same frequency as the interrogating magnetic field burst, and is emitted by the transponder coil prior to receipt of the next interrogation burst.
Type:
Grant
Filed:
September 24, 1998
Date of Patent:
January 9, 2001
Assignee:
Widata Corporation
Inventors:
Ronald J. Hash, Donald K. Belcher, Robert W. Boyd
Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration pulse `blinks` from object-attached tags, to provide a practical, continuous identification of the location of each and every object within an environment of interest, irrespective whether the object is stationary or moving. Correlation-based RF processors determine which signals received spatially diverse antennas coupled to tag transmission readers are first-to-arrive signals as transmitted from any blinking tag. An object location processor carries out time-of-arrival differentiation of first-to-arrive transmissions from any blinking tag to determine where the respective object is located within the environment.
Type:
Grant
Filed:
January 28, 1999
Date of Patent:
November 30, 1999
Assignee:
Widata Corporation
Inventors:
Donald K. Belcher, Robert W. Boyd, Michael A. Wohl
Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration pulse `blinks` from object-attached tags, to provide a practical, continuous identification of the location of each and every object within an environment of interest, irrespective whether the object is stationary or moving. Correlation-based RF processors determine which signals received by tag transmission readers are first-to-arrive signals as transmitted from any blinking tag, and an object location processor carries out time-of-arrival differentiation of these first-to-arrive transmissions from any blinking tag to determine where the respective object is located within the environment. A low power interrogation wand may be employed to refine the location of an object by a user programmed transmission-response exchange between the wand and the tag associated with the object of interest.
Type:
Grant
Filed:
January 21, 1997
Date of Patent:
July 6, 1999
Assignee:
Widata Corporation
Inventors:
Donald K. Belcher, John A. Eisenberg, David S. Wisherd