SU1310772A1 - Meter of phase delay time - Google Patents

Description

one

The invention relates to a radio measuring technique and can be used in measurements with an increased accuracy of the phase time delay of radio engineering and electroacoustic circuits having a large unevenness of the amplitude-frequency characteristic.

The purpose of the invention is to increase the accuracy of measuring the phase delay time of circuits with a large non-uniformity of the amplitude-frequency characteristic.

The drawing shows a structural diagram of the meter phase delay time.

Phase delay time meter contains the first and second 2 high-frequency generators, the first mixer 3, the first filter 4, the phase discriminator 5, the low-frequency generator 6, the first switch 7, the circuit 8 being examined, the second switch 9, the pulse generator 10, the counting phase shifter I, multiplier 12, installation phase shifter 13, integrator 14, output device 15, second mixer 16 and second filter 17.

 The inputs of high-frequency generators 1 and 2 are connected respectively to the inputs of the first mixer 3, the output of which through the first filter 4 is connected to the first input of the phase discriminator 5, the second input connected to the output of the low-frequency generator 6, the output of the phase discriminator 5 is connected to the control input the second high-frequency generator 2. At the same time, the outputs of the high-frequency generators 1 and 2 are connected to the inputs of the first switch 7, the output of which through the circuit 8 under study is connected to the input of the second switch 9, controlling The inputs of both switches are connected to the output of the pulse generator 10, the first output of the second switch 9 is connected to the input of the reference phase shifter 11, and the second output is connected to the nepBbiM input of the second mixer 16, second in-stroke connected to the output of the low frequency generator 6, the output of the second mixer 16 through the filter 17 is connected to the input of the reference phase shifter 11. The outputs of the reference phase shifter 11 and the installation phase shifter 13, the input connected to the output of the first high-frequency generator 1, co25

107722

dineny with the inputs of the multiplier 12, the output of which through the integrator 14 is connected to the output device 15.

The meter works as follows.

High-frequency oscillations from the outputs of generators 1 and 2 with frequencies U) and O) + I and amplitudes U U ,,, iCos (iot +%) and Uj and „2 (cos (w +

10 -t-ft); are fed to the inputs of the first mixer 3, at the output of which, using filter 4, a harmonic oscillation with a difference frequency I is extracted. This oscillation is applied to

 5 the input of the phase discriminator 5, where it is compared in phase with the oscillation of the quartz oscillator 6 low G: often {coming to the second input of the phase discriminator 5. The output

20, the voltage of the phase discriminator 5 is applied to the control input of the second. high frequency generator 2, changing its frequency so that the frequency difference between the high-frequency generators 1 and 2 was equal to the frequency of the low-frequency crystal oscillator 6. Harmonic oscillations are generated at the outputs of high-frequency oscillators 1 and 2, the second one from which is shifted in frequency with respect to the first by a constant value, which is selected by the maximum value of the measured delay C from condition CG / Cp, and is set by the frequency quartz generator of low frequency 6

Harmonic oscillations formed at the outputs of high-frequency generators 1 and 2 are fed to the inputs

40 of the first switch 7. In the position of the first switch 7, indicated in the drawing, the harmonic oscillation U., and „., X cos ((/ (,). Is fed to the input of the circuit B. The mutators 7 and 9 are switched by the generator 10 pulses. In the position of the second switch 9, indicated in the drawing, the output voltage of the investigated circuit 8 and and (t-ir) +

50 is fed to the input of the readout phase shifter 11.

The output voltage of the reference phase shifter 11 is fed to the first 55 input of the multiplier 12, where it is multiplied with the voltage of the first high-frequency generator 1 fed to the second input of the multiplier 12 through the setting phase shifter 13,

As a result of multiplying these voltages and integrating the output of the integrator 14, the voltage is released, KOTOppe is recorded by the output device 15. Then, the voltage phase U is passed through the setting phase shifter 13 to obtain the zero value of the integrated voltage.

In opposite positions of switches 7 and 9 through the circuit under study 8, a frequency-shifted Ug UJ Gos () (t-T) + + oscillation passes to the input of the second mixer 16, where it mixes with the frequency of a low-frequency crystal oscillator 6. At the output of the second mixer 16, using the filter 17, an oscillation with the initial frequency U) is selected, which also passes through the reference phase shifter I1 to the input of the multiplier 12. At that, the phase shift introduced by the circuit under study

8 increases by

An additional phase shift 44 is compensated and recorded with a reference phase shifter 11, restoring the zero value of the integrated voltage on the output device 15, and the phase delay time of the circuit 8 under study is determined by the formula T

- I .

The proposed meter in comparison with the prototype provides a significant increase in the accuracy of measuring phase

  .h

the delay time of the circuits with a large non-uniformity of the amplitude-frequency characteristic due to the use of a single frequency conversion of the mixed oscillation with the oscillation frequency of the low-frequency crystal oscillator, which makes it possible to restore the original frequency value without the use of special frequency shifting devices. This eliminates the effect of spectral components on the signal carrying useful information.

Editor A. Ogar

Compiled by M. Katanov

Tehred L. Serdyukova Proofreader M.Sharoshi

Order 1888/43. Circulation 371. Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Claims (1)

Invention Formula A phase delay meter containing the first high-frequency generator, the input and output terminals for connecting the circuit under study, the setting and reading phase shifters, the outputs of which are connected to the multiplier inputs, the output connected via an integrator to the output device, and a low-frequency generator, while the setting input the phase shifter is connected to the output of the first high-frequency generator, characterized in that, in order to increase the accuracy of measuring the phase delay time of the circuits with a large non-uniform amplitude-frequency response, it additionally introduced a second high-frequency generator, two mixers, two filters, a phase discriminator, two switches and a pulse generator, with the outputs of the first and second high-frequency generators simultaneously connected to the inputs of the first mixer and the first switch output of the first mixer through the first filter is connected to the first input of the phase discriminator, the second input of which is connected to the output of the low-frequency generator, and the output to the controlled input of the second high frequency generator, the output of the first switch is connected to the input terminal of the circuit under study, the output terminal of which is connected to the signal input of the second switch, the control inputs of both switches are connected to the output of the pulse generator, the first output of the second switch is connected to the input of the reference phase shifter, and the second is the first input of the second mixer, the second input connected to the output of the low-frequency generator, and the output through the second filter - with the input of the reference phase shifter.