Communications: electrical – Selective – Interrogation response
Reexamination Certificate
2002-07-08
2010-06-15
Zimmerman, Brian A (Department: 2612)
Communications: electrical
Selective
Interrogation response
C340S572100
Reexamination Certificate
active
07737821
ABSTRACT:
The electronic identification system provides two-way communications between reader and tags using alternating magnetic fields established by the reader and tag. Communication is accomplished by utilizing either a one-step or a two-step modulation process in which the information to be communicated either modulates an alternating magnetic field directly or modulates a periodic signal which modulates an alternating magnetic field. The coil in the reader that is used to establish an alternating magnetic field is transformer-coupled through capacitors to a push-pull driving circuit consisting of four field-effect transistors connected in a bridge arrangement. The coil, capacitors, and coupling circuitry are maintained in a tuned condition by continually adjusting either the driving frequency, the coil inductance, or the capacitor capacitance during communications. A tag utilizes a coil to couple with the reader's alternating magnetic field and a capacitor to resonate the coil, thereby extracting power from the field more efficiently. Transformer coupling of the coil and capacitor is utilized for improved impedance matching. The coil, capacitor, and coupling circuitry can be maintained in a tuned condition by continually adjusting either the coil inductance, or the capacitor capacitance during communications. Certain configurations of the system may require that tuning maintenance be discontinued during the transmission of data.
REFERENCES:
patent: 3223779 (1965-12-01), McFarlane
patent: 3587017 (1971-06-01), Kurusu
patent: 4278980 (1981-07-01), Ogita et al.
patent: 4686708 (1987-08-01), Oki et al.
patent: 4805232 (1989-02-01), Ma
patent: 4839642 (1989-06-01), Batz et al.
patent: 4864633 (1989-09-01), Chatelot
patent: 4942393 (1990-07-01), Waraksa et al.
patent: 5235326 (1993-08-01), Beigel et al.
patent: 5276910 (1994-01-01), Buchele
patent: 5517194 (1996-05-01), Carroll et al.
patent: 6472975 (2002-10-01), Beigel et al.
Beigel Michael L
Frank Steven R
Malm Robert E
Polish Nathaniel
Avid Identification Systems Inc.
Malm Robert E.
Zimmerman Brian A
LandOfFree
Electronic identification system with improved sensitivity does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electronic identification system with improved sensitivity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic identification system with improved sensitivity will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4157296