VEHICLE ANTITHEFT DEVICE Russian patent published in 2007 - IPC B60R25/04 

FIELD: transport engineering; antitheft devices using radio channels.

SUBSTANCE: invention is designed to prevent unauthorized use or hi-jacking of vehicles. Transmitter installed on check station consists of master oscillator, modulating code oscillator, phase keyer, power amplifier, transceiver antenna, duplexer, high frequency amplifier, phase detector, computer, heterodyne, mixer, intermediate frequency amplifier, multiplier and band-pass filter. Receiver installed on vehicle consists of receiving antenna, high-frequency amplifier, detector, two spectrum width meters, frequency doubler, comparator unit, two threshold units, switch, ratio of two frequency divider, narrow-band filter, phase detector, one-pole rectifier and storage unit. Actuating unit contains ignition switch, ignition coil winding, two relays, control switch, storage battery, signaling lamps, sound alarm, sound alarm switch, three capacitors, thyristor, time delay unit, transistor, two resistors and voltage-stabilizing diode. Transponder contains piezocrystal, microstrip antenna, two ridge electrode systems, two busbars and set of reflectors. Receivers in proposed device employ superheterodyne circuit.

EFFECT: increased sensitivity, dynamic range and range of detection.

5 dwg