PULSE RADIO SIGNAL RECEIVER AND LEVEL METER FOR SAID RECEIVER Russian patent published in 1997 - IPC

FIELD: radio engineering, in particular, ground responders of long-range navigation systems. SUBSTANCE: device has frequency converter 1, strip amplifier 2, compensating amplifier 3, delay line 4, linear amplifier 5, filter 6, buffer amplifier 7, three comparators 8, 9 and 12, three gates 10, 11, 13, channel discriminator 14, level meter 15 and amplification control unit 16. Level meter has amplifier 23, N-bit controlled amplifier 24, first comparator 25, control signal generator 26, binary N-bit counter 27, N-1 delay lines 28, second comparator 29, flip-flop 30, differentiating circuit 31, AND gate 32. Input signal is sent through frequency converter and strip amplifier in parallel to level meter and delay line. Level meter is designed as linear device for high-speed automatic amplification control with negative feedback. It outputs information about amplitude of input signal in binary code which is sent through control unit to linear amplifier, which is identical to amplifier of level meter. This alters gain of linear amplifier before it receives pulse from output of delay line. Amplified pulse of intermediate frequency is sent from output linear amplifier through filter and buffer amplifier to first comparator which detect its leading edge without demodulation at half-amplitude level. Second and third comparators detect leading edge of pulse at levels of 0.05 and 0.30 of its amplitude. Outputs of comparators are connected to outputs of receiver through gates which are rendered conducting by channel discriminator if received signal correspond to given frequency. Linear amplifier and three comparators which operate without demodulation of pulses decrease error in detection of pulse leading edge. Feedback in level meter and identity of linear and measuring amplifiers decrease identity of destabilizing factors. Two feedback circuits in level meter increase dynamic range. EFFECT: increased precision of distance measurement, increased effective range. 3 cl, 3 dwg