Variable frequency radio frequency identification (RFID) tags

Details Variable frequency radio frequency identification (RFID) tags Variable frequency radio frequency identification (RFID) tags

2007-12-04

2007-12-04

Pham, Toan N. (Department: 2612)

Communications: electrical

Condition responsive indicating system

Specific condition

C340S572700, C340S010200

Reexamination Certificate

active

11555699

ABSTRACT:
Various radio frequency identification (RFID) tags are described that dynamically vary their resonant frequency to reduce or eliminate the potential effects of electromagnetic “tag-to-tag” coupling. An RFID tag, for example, includes a main antenna tuned to a first resonant frequency, and switching circuitry that dynamically changes the resonant frequency of the main antenna. The switching circuitry may selectively couple electrical elements, such as capacitive elements, inductive elements, or combinations thereof, to vary the resonant frequency of the RFID tag. The RFID tag may include a sensing circuit that determines when to selectively couple the electrical element to the main antenna to adjust the resonant frequency of the main antenna.

REFERENCES:
patent: 4260990 (1981-04-01), Lichtblau
patent: 4782345 (1988-11-01), Landt
patent: 4870391 (1989-09-01), Cooper
patent: 5142292 (1992-08-01), Chang
patent: 5446447 (1995-08-01), Carney et al.
patent: 5771021 (1998-06-01), Veghte et al.
patent: 5892300 (1999-04-01), Rydval
patent: 5940043 (1999-08-01), Canipe et al.
patent: 5977875 (1999-11-01), Lin et al.
patent: 6037879 (2000-03-01), Tuttle
patent: 6043792 (2000-03-01), Finlayson
patent: 6070803 (2000-06-01), Stobbe
patent: 6107920 (2000-08-01), Eberhardt et al.
patent: 6147605 (2000-11-01), Vega et al.
patent: 6163260 (2000-12-01), Conwell et al.
patent: 6229444 (2001-05-01), Endo et al.
patent: 6346884 (2002-02-01), Uozumi et al.
patent: 6466131 (2002-10-01), Tuttle et al.
patent: 6480110 (2002-11-01), Lee et al.
patent: 6617962 (2003-09-01), Horwitz et al.
patent: 6624743 (2003-09-01), Ikefuji et al.
patent: 6861993 (2005-03-01), Waldner
patent: 6889036 (2005-05-01), Ballweber et al.
patent: 2002/0097153 (2002-07-01), Youbok et al.
patent: 2002/0180588 (2002-12-01), Erickson et al.
patent: 2002/0196126 (2002-12-01), Eisenberg et al.
patent: 1 026 832 (2000-08-01), None
patent: 1 045 526 (2000-10-01), None
patent: 1 061 663 (2000-12-01), None
patent: 0 829 921 (2001-06-01), None
patent: 2 757 952 (1998-07-01), None
patent: 2 307 379 (1997-05-01), None
patent: 2 321 726 (1998-08-01), None
patent: WO 98/05088 (1998-02-01), None
patent: WO 98/31070 (1998-07-01), None

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