SU368552A1 - AUTOMATIC MEASURING FREQUENCY FILL - Google Patents

Description

one

The invention relates to the field of radio measurements and can be used in automatic systems.

The known automatic frequency meter for filling radio pulses contains a series-connected intermediate frequency amplifier, a limiter, a frequency detector, a generator frequency tuning unit, a tunable oscillator, a modulator, and an indicator.

The disadvantages of this meter are significant error and large measurement time.

The purpose of the invention is to reduce the error and shorten the measurement time.

This is achieved by introducing a pulse time shift block, an adder and an amplitude detector into the proposed meter, a pulse time offset block being connected between one of the totalizer and modulator inputs, and a modulator output connected to the second input of the adder, the frequency detector output is connected to the input of the amplitude detector and through the low-frequency amplifier and the rectifier to the generator frequency tuning control unit.

FIG. 1 is given the block diagram of the described meter; in fig. 2 - time diagrams, as follows: his work; in fig. 3 - timing diagrams explaining the operation of the unit of the time shift of pulses.

The automatic frequency meter for filling the radio pulses contains a series-connected intermediate frequency preamplifier (PCF) /, adder 2, intermediate frequency amplifier 3 (UPCH), limiter 4, frequency detector 5, video amplifier 6, amplitude detector 7,

low-frequency amplifier 8 (ULF), rectifier 9, generator frequency tuning unit 10, tunable generator 11, modulator 12, as well as pulse time shift unit 13 and indicator 14. The generator frequency tuning control unit consists of a DC amplifier 15 and integrator 16. The pulse time shift block consists of the detector 17, a kip-relay 18, a driver 19 pulses, triggers 20,

21, matching circuits 22, 23, accumulators 24, 25, differential amplifier 26, pulse generator 27 and integrator 28. Unit 13 is connected to one of the inputs of adder 2 and modulator 12, and the output of modulator 12 is connected to the second input of adder 2; The output of the frequency detector 5 is connected to the input of the amplitude detector 7 through the video amplifier 6 and through the low-frequency amplifier 8 and the rectifier 9 to the block 10.

The frequency of filling the radio pulses is measured as follows. In the middle between the radio pulses of the measured sequence with a repetition period T (Fig. 2, a), using block 13, an artificial delay of T / T delayed by radio frequency with a repetition frequency Ti - T is introduced (Fig. 2.6). The delayed sequence of radio pulses arrives at one input of the modulator 12, and the frequency of the tunable oscillator 11 arrives at its other input (Fig. 2, c). A sequence of radio pulses is removed from the modulator output, the filling frequency of which is equal to the frequency of the tunable generator / gene. This sequence is fed to one input of adder 2, and to the other its input receives a measured sequence of frequency pulses / X. The pulse sequence after the adder (Fig. 2, d) consists of radio pulses with a filling frequency equal to the measured fx, and radio pulses with a filling frequency equal to the frequency of the tunable generator / gene. This sequence through the OO frequency 3 and limiter 4 is fed to the frequency detector 5 , from the output of which the sequence of video pulses is removed (Fig. 2, d), the amplitude of which is proportional to the filling frequencies fx and / gene. Since the filling frequencies are different, information about the magnitude of their difference lies in the amplitude mod the sequence of these video pulses. The amplitude detector 7 selects the frequency envelope of the measured radio signals (Fig. 2, e), which is amplified by the ULF 8 (Fig. 2, g), rectified by rectifier 9 and fed to block 10. The latter changes the frequency of the tunable generator 11 until it is compared with the measured frequency, i.e., the amplitudes of the video pulses are proportional to the filling frequencies fx and freH .. The frequency is measured by the indicator 14, which uses a frequency meter.

The time shift of the radio pulses and the value of T / 2 is carried out by block 13, a possible embodiment of which is presented in an analog-digital form in FIG. I. Investigated sequence of radio pulses enters the detector 17 (Fig. 3, a). The detected video pulses (Fig. 3, b) trigger the KIPP relay 18 (Fig. 3, e) and the trigger 21 (Fig. 3, d) and simultaneously return to the initial state the trigger 20 (Fig. 3, d). At the first moment, the kip-relay 18 forms a pulse, the duration of which is arbitrary, but less than half of the least expected period of the radio pulse sequence under study. The falling edge of the KIPP relay shaper 19 forms a standard pulse (Fig. 3, e), which returns the trigger 21 to the initial state and triggers the trigger 20. The pulses from the flip-flops 20, 21 arrive at the joint circuits 22, 23 through which The action of these pulses on the accumulators 24, 25 passes pulses from the generator 27 of the pulses (Fig. 3, g, i). The output voltages of the accumulators, depending on the number of incoming pulses from the generator 27, are compared at the differential amplifier 26 and the difference of these voltages (Fig. 3, k, l, m) through the integrator 28

Adjusts the duration of the KIPP relay. The duration of a kipp-relay pulse varies as long as the output voltages of the accumulators are not equal. In this case, the duration of the pulse of the KIPP relay will be equal to

half of the period of the studied sequence of radio pulses with an accuracy of one period of repetition of the pulses of the generator 27. The pulses from the generator 19, shifted by one half of the period of the sequence of radio pulses under study, are fed to the modulator 12.

Subject invention

Automatic meter for filling frequency of radio pulses, containing serially connected intermediate frequency amplifier, limiter, frequency detector, frequency tuning control unit

generator, tunable generator and modulator, as well as an indicator characterized in that, in order to reduce the measurement error of the frequency of the radio pulses and the measurement time, an adder, an amplitude detector and a unit for the time shift of the pulses are inserted in it between the one of the adders and the modulator, and the output of the modulator is connected to the second input of the adder, the output of the frequency detector is connected to the input of the amplitude detector and through a low-frequency amplifier and rectifier to the control unit and tuning the oscillator frequency.

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