SU779896A1 - Device for measuring short-duration of frequency instability - Google Patents

Description

(54) DEVICE FOR MEASURING SHORT-TERM INSTABILITY OF FREQUENCY

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This invention relates to the field of radio engineering,.

The schemes of frequency instability meters are known, based on the principle of measuring the duration of the oscillation period of the difference frequency obtained by shifting the frequencies of the reference and tested oscillators.

Devices are known that contain a control unit, counters, generators, and a register {i.

A disadvantage of the known devices is the low measurement accuracy.

Of the known devices, the device closest to that proposed by its technical essence is a device containing a frequency meter, a reference oscillator, a mixer, and a multiplier 2,

A disadvantage of the known device is that it allows to measure short-term frequency instability in the steady-state mode of oscillations and has a low accuracy of frequency measurement in a transient mode — in the mode of establishing oscillators of oscillators operating continuously, as well as quartz oscillators.

shock excitation, the oscillations of which are rigidly attached to the leading edge of the triggering pulses.

The low accuracy of the measurement of short-term frequency instability is due to the fact that the oscillating time in the generator and their measurement time are not synchronized,

The purpose of the invention is to improve the measurement accuracy,

This goal is achieved by the fact that a device for measuring short-term frequency instability, containing a frequency meter and a series-connected reference oscillator, mixer and multiplier, is inserted along the sequentially connected clock generator, a kipp-relay and a key, serially connected first delayed-pulse generator, first time selector and the second time selector, as well as the second generator of delayed pulses, the input of which is connected to the first output of the synchronizing generator, the second; the output of the latter is connected to in ode of the first generator of delayed pulses, while the output of the second generator of delayed pulses is connected to the second input

gToporo time selector whose output is connected to the first input of the frequency meter, the second input of the latter is connected to the output of the first time selector, the second input of which is connected to the output of the multiplier.

FIG. 1 shows a block diagram of the device; in fig. 2 shows the time waveforms of the signal, explaining the principle of operation of the device.

The device contains a synchronous generator 1, Kip-relay 2, key 3, power source 4, generator 5, mixer 6, reference generator 7, multiplier 8, time selector 9, frequency meter 10, generator 11 delayed pulses, generator 12 delayed pulses, time selector 13.

The pa6ofaeT device is as follows.

The triggering pulse of the synchro-generator 1 (see FIG. 2 a) is supplied in parallel to the Kipp-relay 2, to the generators 11.12 delayed pulses. Kip-relay 2 forms a blanking pulse (see Fig. 26), which opens the switch 3. Through the key 3, the supply voltage is supplied to the generator 5. The signal from the generator 5 is fed to the mixer 6, where it is mixed with the signal of the reference generator 7 . Output-. The difference difference frequency signal from the mixer is multiplied many times in multiplier 8 (see Fig. 2d), made according to the frequency compiler circuit, and then goes to the time selector 9.

The selector 9 transmits a signal to the first input of the frequency meter 10 (see FIG. 2 g) in the presence of a pulse from the generator 11 delayed pulses at the second input of the time selector 9 (see FIG. 2 c).

The signal at the second input of the frequency meter 10 (see Fig. 2 e) comes when there are 12 delayed pulses from the generator at the second input of the time selector 13 (see Fig. 2 g). By varying the pulse delay from the generators 11,12 delayed pulses relative to the pulse from the synchro-generator, it is possible to measure short-term frequency instability from the moment

supply power to the generator under study before turning it off.

The averaging time (measurement) of the frequency is set on the frequency meter. The frequency meter can provide information in the form of two samples, corresponding to the beginning and end of the measurement time, over which the short duration of the frequency instability is determined. As a frequency meter, a reverse type frequency meter can be used.

This device for measuring short-term frequency instability allows high-resolution measurements of 5 short-term frequency instabilities of generators in a transient mode.

Claims (2)

1. US patent number 3900914, G 01 R 23/02, 30.09.75. 0 2. Equipment for frequency and N time measurements. Ed. A.P.Gorshkova M., Sov. radio, 1971, p.249, fig. 8.29.