Pulsed electronic article surveillance systems

摘要

An electronic article surveillance (EAS) system includes a transmitting antenna, a driver operable for exciting the transmitting antenna, a receiving antenna and circuitry connected to the receiving antenna for improving the quality of transmissions from the transmitting antenna. The driver excites the transmitting antenna at a preselected system operating frequency and the circuitry connected to the receiving antenna improves the quality of transmissions from the transmitting antenna by lessening harmonics of the operating frequency in the transmissions. The harmonics are attributable to protection diodes connected to the receiving antenna for limiting voltages impressed thereon and otherwise adversely impacting on the receiver tag signal processing circuitry. The harmonic lessening circuitry is connected in parallel with the protection diodes and is operative to lessen protection diode harmonic generation. <IMAGE>