Anti-theft detecting system

摘要

An anti-theft detection system. A target (11) comprising a frequency multiplier is affixed to goods in a retail store. A low power radio frequency source is placed near the exits to the retail store, and the target (11) remits the frequency and harmonics of the frequency transmitted by the radio frequency source when located near the radio frequency source. A detector also located near the exits to the retail store detects the harmonics, compares the amplitude of the harmonics and original frequency to stored values and commands an alarm, thereby allowing for an apprehension of shoplifters.