SU987787A1

SU987787A1 - Frequency-modulated signal demodulator

Info

Publication number: SU987787A1
Application number: SU803222720A
Authority: SU
Inventors: Александр Зуберович Кумехов; Анатолий Михайлович Плотников
Original assignee: Производственное Объединение "Телемеханика"
Priority date: 1980-12-23
Filing date: 1980-12-23
Publication date: 1983-01-07

Description

(5) ДЕМОДУЛЯТОР ЧАСТОТНО-МОДУЛИРОВАННЫХ (5) FREQUENCY-MODULATED DEMODULATOR

Изобретение относитс к радиотехнике и может использоватьс при построении демодул торов частотно-модулированных сигналов в технике передачи данных.The invention relates to radio engineering and can be used in the construction of demodulators of frequency modulated signals in a data transmission technique.

Известен демодул тор частотно-модулированных сигналов, содержащий последовательно соединенные усили- ;. тель-ограничитель и формирователь фазирующих импульсов, последователь-, но соединенные фильтр нижних частот |И пороговое устройство, а также элемент совпадени } Однако известный демодул тор невозможно использовать при скорости модул ции, соизмеримой с характеристическими частотами передачи.Known demodulator frequency-modulated signals, containing a series-connected force;. tel-limiter and phasing pulse shaper, sequentially but connected low-pass filter | And a threshold device, as well as a coincidence element} However, a well-known demodulator cannot be used at a modulation rate commensurate with the characteristic transmission frequencies.

Цель изобретени - повышение крутизны амплитудно-частотной характеристики при скорости модул ции, со измеримой с характеристическими частотами передачи. СИГНАЛОВThe purpose of the invention is to increase the steepness of the amplitude-frequency characteristic at the modulation rate, with measurable characteristic transmission frequencies. SIGNALS

Указанна цепь достигаетс тем, что в демодул тор частотно-модулированных сигналов, содержащий последог вательно соединенные усилитель-ограничитель и формирователь фазирующих импульсов, Последовательно соединенные фильтр нижних частот и пороговое устройство, а также элемент совпадени , введены два одностабиль;ных элемента, входы которых объеди|нены между собой и подсоединены к выходу формировател фазирующих импульсов и первому входу элемента совпадени , и О-триггер, установочIJ ный вход которого подключен к выходу первого одностабильного элемента, а тактовый вход - к выходу элемента совпадени ,.второй вход которого подключен к выходу второго одностабильногоThis circuit is achieved by the fact that a demodulator of frequency-modulated signals containing successively connected limiting amplifier and shaper of phasing pulses, successively connected low-pass filter and threshold device, as well as a coincidence element, are entered into two single-stable elements whose inputs | interconnected and connected to the output of the phasing pulse generator and the first input of the coincidence element, and the O-flip-flop, the set input of which is connected to the output of the first one the stable element, and the clock input to the output of the coincidence element, the second input of which is connected to the output of the second one-stable

2Q элемента, при этом выход D-триггера соединен с входом фильтра нижних частот.2Q element, while the output of the D-flip-flop is connected to the input of the low-pass filter.

Claims

The drawing shows the structure {g: - on the electrical circuit of the proposed demodulator; 398 Frequency-modulated signal demodulator: contains amplifier-limiter 1, shaper 2 phasing pulses, low-pass filter 3, threshold device C, 5-coincidence element, single-stable elements 6 and 7, and D-trigger 8. The demodulator works as follows. The input signal, converted by the limiting amplifier 1 to square pulses, is fed to the shaper of 2 phasing pulses. Shaper 2 at times of nocTyfrfi and at its input of fronts and decays of square pulses depending on the input signal. The one-stable elements 6 and 7 are triggered by the decay of each phasing pulse except the first one, where the trigger goes on the leading edge. In this case, only phasing pulses with a frequency of 2 ff will pass through the output of element 5. These pulses set the D-flip-flop 8 to state 1. Each time the one-stable element 7 is started, an impulse is formed at its output, the duration of which is somewhat less than. By dropping this pulse, the D-flip-flop 8 is set to the .0 state. Thus, when a frequency-modulated signal arrives at the input of the demodulator with characteristic frequencies fj and the output of the D-flip-flop B, a sequence of pulses appears either with a skuiness of close to 1 (signal with frequency fn) or an infinitely large duty cycle ( f) frequency signal. The output of the low-pass filter 3 produces a signal proportional to the constant component of the output pulses of the D-flip-flop 8. The signal from the output of the filter 3 is then fed to the threshold device i, the output of which is the demodulated signal. Thus, the proposed demodulator, in comparison with the known one, provides an increase in the steepness of the amplitude-frequency characteristic at a modulation rate commensurate with the characteristic frequencies and, by this, etc., the scope of its application. Claims of the invention A frequency modulated signal demodulator comprising a series-connected amplifier limiter and a phasing pulse shaper, a series-connected low-pass filter and a threshold device, as well as a coincidence element, characterized in that in order to increase the amplitude-frequency response slope at the modulation rate , commensurate with the characteristic frequencies, two one-stable elements are introduced into it, the inputs of which are interconnected and connected to the output of the forms a phasing pulse impulse to the first input of the eleven-match, and a D-flip-flop, the setup input of which is connected to the output of the first one-stable element, and the clock input to the output of the matching element, the second input of which is connected to the output of the second one-stable element, while the output D- The trigger is connected to the bottom filter input. Sources of information taken into account in the examination, .1 USSR Copyright Certificate № k7321S, cl. H 03 D 3/02, 05.06.72 (prototype).

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