AUTOMOTIVE ANTITHEFT DEVICE Russian patent published in 2011 - IPC B60R25/04 

FIELD: transport.

SUBSTANCE: invention relates to automotive antitheft devices exploiting radio channel and surface acoustic wave responder. Proposed device comprises transmitter mounted at control station, receiver, actuator and responder mounted on transport facility. Transmitter comprises transceiving antenna, master oscillator, modulation code generator, phase manipulator, power amplifier, duplexer, two HF amplifiers, phase detector, computer, local oscillator, four mixers, intermediate frequency amplifiers, four 90°-phase shifters, two adders, five multipliers, four harrow-band filters, two amplitude detectors, two low frequency filters, two amplifiers, two adjustable delay units, range indicator, angle indicator, two frequency doublers, two frequency halvers, two differentiators, phase metre and receiving antenna. Receiver arranged in transport facility comprises receiving antenna, HF amplifier, frequency doubler, two spectrum metres, comparator, two threshold units, switch, frequency halver, narrow-band filter, phase detector, unipolar gate, accumulator 21, two mixers, local oscillators, two intermediate frequency amplifiers, two 90°-phase shifters, amplitude detector and switch. Actuator unit comprises switch, ignition coil, two relays, two switches, ignition switch, storage battery, four light indicators, sound alarm, three capacitors, thyristor, time delay unit, transistor, two resistors and stabiliser diode. Responder comprises piezo crystal, microstrip antenna, electrodes, two busses and set of reflectors 56. Proposed device suppresses false signals (interferences) received in additional channels and uses arbitrary correlation functions.

EFFECT: higher selectivity, noise immunity and accuracy of range finding.

5 dwg