SECURITY ALARM SYSTEM Russian patent published in 2012 - IPC G08B26/00 H04B5/02 

FIELD: physics.

SUBSTANCE: security alarm system has a remote control device, transceiving devices and radio-frequency labels. A transceiving device, which is installed on the monitored facilities, has a sensor for intactness of the locking-sealing device, a memory element, an encryptor, a receiver, a transceiving antenna, a decoder, a pulse generator, a transmitter, read-only memory, a reference clock, a phase-shift keying device, heterodynes, mixers, a third intermediate frequency amplifier, a power amplifier, a duplexer, a high frequency amplifier, a second intermediate frequency amplifier, a multiplier, a band-pass filter and a phase detector. The remote control device has a reference clock, a phase-shift keying device, mixers, heterodynes, a first intermediate frequency amplifier, a power amplifier, a control unit, a pulse generator, an encryptor, a transmitter, a transceiving antenna, a decoder, a receiver, a duplexer, a first low frequency generator, a signalling unit, a memory unit, a comparator and a second low frequency generator. The radio-frequency label has a piezoelectric crystal, a microstrip transceiving antenna, electrodes, buses and a set of reflectors.

EFFECT: high efficiency of the security alarm system owing to use of two frequencies, phase-shift keyed composite signals and radio-frequency labels operating on acoustic surface waves.

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