초록 ▼

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 transpon

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.

대표청구항 ▼

1. A reader comprising:a processor coupled to a host computer; at least a first electrode; an exciter, coupled to the processor and at least the first electrode, for generating and transmitting an electrostatic excitation signal having a first carrier frequency; at least a second electrode; a receiv

1. A reader comprising:a processor coupled to a host computer; at least a first electrode; an exciter, coupled to the processor and at least the first electrode, for generating and transmitting an electrostatic excitation signal having a first carrier frequency; at least a second electrode; a receiver, coupled to at least the second electrode, for receiving an RF signal via electrostatic means; and a detector circuit, coupled to at least the second electrode, for detecting an alarm signal having a second carrier frequency, the detector circuit amplifying the alarm signal if the second carrier frequency is sensed.