SYSTEM OF RADIO-FREQUENCY IDENTIFICATION ON SURFACE ACOUSTIC WAVES Russian patent published in 2011 - IPC G01S13/00 

FIELD: radio engineering.

SUBSTANCE: system includes receiver-transmitter with horn receiving-transmitting antenna, delay lines on surface acoustic waves (SAW), antennae, receiving-transmitting interdigital transducer (IT), and reflection ITs. Every m delay lines with various distances between IT are combined into n groups which in their turn are combined into the appropriate groups. Radio-frequency guide marks are located at guard stations each of which includes n guarded objects. Receiver-transmitter includes control device, frequency synthesiser, pulse generator, antenna switch, receiver with detector, device for shaping rectangular pulses, pulse counting device, emergency alarm device, narrow-band filter with tuning frequency f_H=f₁, delay line with delay time τ₃=2mτ, band-pass filter with tuning frequency f_H=f₁, phase detector, recording unit and timer.

EFFECT: higher object guard efficiency by using reliable system and monitoring of actions of security patrols.

3 dwg