The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 2002
Filed:
Sep. 08, 1999
Victor Vega, Hercules, CA (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A contactless programmable electrostatic Radio Frequency Identification (RFID) reader that also serves as an Electronic Article Surveillance (EAS) reader is described. The RFID/EAS reader contains a detector circuit for detecting the presence of a signal carrier frequency transmitted by the transponder in response to a signal from the reader. The detector circuit has a resonator circuit which is connected to a receiver electrode. The resonator comprises a piezoelectric element with a high quality factor 'Q' at the resonant frequency to enhance sensitivity. The alarm carrier signal is rectified and fed to either a peak detector or an envelope detector circuit. A voltage source generates a voltage threshold to allow for operating range adjustment. A comparator compares both voltages and generates an alarm signal if the voltage signal reaches the threshold voltage. The RFID/EAS further having the capability to read the RFID contents. Alternatively, an electrostatic EAS reader (without RFID capability) having a substantially similar detector circuit is also described.