SU742865A1 - Meter of group time delay of four-pole networks - Google Patents

Description

The invention relates to a measurement technique and can be used to measure group delay times of two-port networks.

A meter is known in which Measurement of the group delay time is made by the phase shift of the amplitude-modulated signal envelope after passing through a quadrupole 1J under study. Its disadvantage is a low measurement accuracy.

Also known is the group delay time meter, which allows measuring the group delay time of quadrupoles in a pulsed mode, containing a high frequency generator, a modulator connected between the output of the high frequency generator and the output of the video pulse generator, the output of the modulator is connected to the inputs of the first ai detector, and the test quadrupole, the output of KOTOYUGO through the second amplitude detector and the filter connected in series is connected to one of the indicator inputs, and the output of the first amplitude

the detector is connected via a filter to the atorome input of the indicator (2),

In this meter, Trr is determined by the differences: the phases of the first harmonics of the bend at the input and output of the studied quadrupole, which are separated by filters 5

The poor quality of this meter is low: the accuracy of the measurement

10 time lag time.

The aim of the invention is to improve the accuracy of measuring the group time delayed.

This is achieved by the fact that a known meter, a holding high frequency generator, connected to a modulator, a generator of video pulses, two amplitude detectors, one of which is connected to the input terminal

20 to disconnect the quadrupus test being investigated, and the other to its output terminal, and the indicator, introduced an amplifier-limiter connected to the second input of the modulator and the first input of an additional generator, two peak detectors, two blocks for comparing signals, the first signals to which are connected with peak detectors, stabilization unit

D1l on, tsaoe:, p.nnekky vzedenkomu one input to the second unit for comparing the signals, and the second - to igudnomu AIS detector and the Introduction ™ Deniau sequentially soednnanye vychitatelj zlektronpy kommutatotz and a storage element connected to the source indikatoruf stabilized voltage to the 1st ztsitonng cheplra |: pole j paddock junction to ne4) BOTvii aiysn.T ioTy: aKoivs to the detector, and .com - to the first peak TOjjy detK and a readout controller with a control of the direct input from the KONS-fyTaTO apron and a control panel by a questionnaire; booster amplifier / g, block output for stabilization of the amplitude, schl to the atortlm input of the calculator and the second detector, and the stabilizing voltage KCTO-ini-JK to the second inputs of the first and the third blocks of the first generator, which is connected to the second generator, ,

In the drawing, rTpKKej3, eKa with the structure1 diagram of the group meter indicator 3 a Pa 3 for the a and a-i

The group lag time meter contains a frequency generator of frequency Kofi .1, amplifier-limited refib 2,: a generator of video pulses 3 motor 4f d7 (OPC generator 5, amplitude; evil detectors 6, -7 j research 5K quadrupole 8, peak detectors 9 , 10, block AND for stub -; | Pizatki amplitudes of reference four-terminal 12, blocks -13, i4 for comparing signals, reference to stabilized voltage 15, subtractor 16: electronic combator 17, key element 18, and plug 19 „

The meter operates as follows. The voltage U, Ufn / S / n cvt from the output of the high-frequency generator is fed to the input of the modulator 4. where it is modulated by square pulses M,: received from the generator 3 s

with the help of amplification of the body, the voltage from the output of the modulator 4 is fed to an additional generator 5, which is in an underexcited state, in which at the time of the appearance of voltage from the output of the modulator 4, oscillations of the amplitude increase linearly,

In order to realize this phenomenon, it is necessary that the frequency of the oscillating circuit of the additional generator 5 be close to the frequency of the exciting voltage; as a result, the adjustment elements of the generators 1 and 5 must have a mechanical or electrical connection,

The breakdown of the oscillations of the additional hickerator 5 is made negatively by a half-voltage of the voltage and the output of the amplifier limiting device 2 "Linearly increasing 1" to the amplitude of the oscillations are simultaneously amplified

the detector to the quadrupole 3 under study .. By detecting in the amplitude detector 6 a voltage at the output; and: next, the three-pole 8 bucks are shifted with respect to the capacitor, at the input of the quadrupole 8 ng; group delay time; T

Output naprnzkekke a and lktuhsnogo; etektora b Cherazi ztelonkgly quadripole 12 is supplied to a input of the first faces of the detector 9, the output voltage which is supplied to one input of the first block for cpciBHeHHH with and drove about 13, where is compared with the voltage supplied from the source stabilized voltage 15 .J JArpl (; skimming, pours out to additional generator 5, adjusting the maximum value of the amplitude of oscillations to a value equal to the voltage of the source of the stabilized voltage (15). close to zero.

The output voltage of the quadrupole 8 under study after detection in the amplitude detector 7 is fed to the input of block 11 ". The second input receives voltage from the output of block 14, which is connected to the second input: RM to the output of the source-driven voltage 15 and to the output of the second peak detector 10 .

The maximum value of the output voltage of the unit 11 due to the feedback is also maintained equal to the value of the voltage of the source of the stabilized voltage 15,

The output voltage of block 11 is fed simultaneously to the input of the second peak detector U and to the input of the calculator 16 ,. where the voltage from the output of the reference two-port network 12 also arrives. The maximum values of these voltages are equal to the voltage value of the source of the stabilized voltage 15, Due to the fact that these voltages are shifted in time by the value of the group delay time of the four-pole network 8 studied, the voltage at the output of the subtractor is proportional to fjp,

The voltage with the amplitude Ug is groupable to the group delay time of the studied quadripole 8 from the output of the subtractor 16 through the electronic switch 17 is fed to the input of the storage element .18. The electronic switch 1 is open only at the moment of action of the pulse, which is fed to its second input from the output of the amplifier-limiter 2.

The amgshituda of the output voltage of the .18 E booster element is proportional to

Claims (1)

Claim A four-terminal group delay meter containing 20 high-frequency generator connected to a modulator, a video pulse generator, two amplitude detectors, one of which is connected to the input terminal for connecting the studied four-terminal device, and the other to its output terminal, and an indicator , © t lich a. y u with y - that in order to increase the accuracy of measurement into it. an amplifier limiter connected to the second input of the modulator and the first input of the additional generator, two peak detectors, two blocks for comparing signals, the first inputs of which are connected to peak detectors, an amplitude stabilization unit connected by one input to the introduced second block are introduced for comparing signals, and the second - to the second amplitude detector, as well as a series-connected subtractor, an electronic switch and a storage element connected to the indicator, a stabilizer source voltage and a reference four-terminal connected to the first amplitude detector by the input, a. the output is to the first peak detector, torus and subtracter, [and the control input of the electronic switch is connected to the output of the limiter amplifier, the output of the amplitude stabilization unit is connected to the second inputs of the subtractor and the second peak detector, and the stabilized voltage source is connected to the second inputs the first and second blocks for comparing signals, while the output of the first one is connected to the second input of the additional generator.