SU1709242A1 - Device for measuring amplitude-frequency and phase characteristics of quadriopoles with frequency converter - Google Patents

Abstract

The invention relates to a radio measuring technique and can be used to measure the phase and amplitude-frequency characteristics of quadrupoles with a frequency converter (mixer) in the ultra-high frequency range. The purpose of the invention is to expand the functionality of the device by measuring the suppression of the "mirror" channel in a test quadripole with a frequency converter. The device contains oscillating frequency generators 1 and 2, control unit 3, electronic switch 4, search generator 5, dividers 6.25 signals, attenuator 7, switches 8, 12, 13, 21, 24 and 26, mixers 9, 15 phase-locked loop adder 10, phase shifter 11, phase detectors 16 and 22, synchronous detector 17, search generator control block 18, quadrupole under test with frequency converter 19, reference mixer 20, intermediate frequency generator ** **. , mixer 27 intermediate frequency measuring channel Intermediate frequency reference channel mixer 28, an indicator 29, a decision unit 30 connected appropriately. 1 il. 3VIO Yu) ^ GO > &

Description

The invention relates to a radio metering technique and can be used to measure the phase frequency and amplitude-frequency characteristics of quadrupoles containing a frequency converter (mixer) in the ultra-high frequency (microwave) range.

It is known that in the process of conversion5 of the microwave input signal in the tested quadripole with a frequency converter, the output signal of the intermediate frequency can be obtained in accordance with the expression

(Tp Q) c-a) f;

C () lh UV - fWc.

where sos is the frequency of the signal;

ftV is the frequency of the local oscillator;

Cf / riM intermediate frequency, i.e. by up and down conversion,

In test quadripoles with a frequency converter, one of two transformations is usually selected, and the other is parasitic and filtered. The magnitude of the suppression of this parasitic (mirror) transformation is one of the main characteristics of any quadrupole with a frequency converter (mixer),

A device containing two oscillating frequency oscillators, their control unit, controlled attenuator, reference element, phase locked loop mixer, quadrangular under study, intermediate frequency generator, phase atathoress tuning block, phase detector, intermediate frequency mixers of the measuring and reference channels, dual channel amplitude detector are known. -phase indicator and additional mixer; ,

A disadvantage of this device is the impossibility of measuring the magnitude of the phase shift introduced by the device under test with a frequency converter into the intermediate frequency signal during the conversion process and the impossibility of measuring the characteristics on the main and parasitic reception channels.

The closest to the present invention is a device containing two generators, a control unit, two signal splitters, an attenuator, six switches, two phase locked loaders, an amplifier, a dose detector, a quadrupole with frequency converter, a reference mixer, a tunable intermediate frequency generator, intermediate frequency mixer of the measuring channel, intermediate frequency mixer of the reference channel, indicator

and solver.

The disadvantage of this device is that it cannot measure at each of the two types of conversion — basic and specular. Signal

O the first variable intermediate frequency in the device is formed by adding or subtracting the frequencies of the signals of the two oscillating frequency oscillators, the type of conversion being upper or lower

5 is determined by the initial setting.

PLL systems with device release and

D / 1I particular type of device remains

unchanged during its operation.

This prevents the measurement of inhibition.

0 of the mirror channel in the test quadrupole with a frequency converter with respect to the basic type of conversion.

The purpose of the invention is to expand the functionality of the device by measuring the suppression of the mirror channel in a test quadrupole with a frequency converter.

This goal is achieved by the fact that

0 a device for measuring amplitude-frequency and phase-frequency characteristics of quadrupoles with a frequency converter, containing two oscillating frequency oscillators, the first control inputs of which are connected to the first and second outputs of the control unit, the third output of which is connected to the input of a tunable intermediate frequency generator, the third output of which is connected with the second

0 by the input of the second phase detector, the output of the first oscillator of the oscillating frequency is connected to the input of the first divider signal;} catch and one of the inputs of the first mixer of the phase-locked loop, another pass

5 of which is connected to the output of the second oscillating frequency generator, simultaneously connected to the second (heterodyne) inputs of the tested four-port network with a frequency converter and a reference mixer, the first input of which is connected to the moving contact of the third switch, the first fixed contact of which is connected to the first fixed contact of the fourth switch, mobile KOtiTakT which is connected to the output of the amplifier, the input of which is connected to the moving contact of the first switch, the first fixed contact otorrhea through the attenuator is connected to one of the first divider output signal and the other

the output of which is connected to the first fixed contact of the second switch, the movable contact of which is connected to the first (signal) input of the tested quadrupole with a frequency converter, the output of which is connected to the first input of the intermediate frequency mixer of the measuring channel, the second input of which is connected to the second input of the intermediate frequency mixer. channel and the second output of a tunable intermediate frequency generator, in turn, connected to the second input of the second mixer A frequency tuning, the first input of which is connected to the output of the first phase locked loop mixer and the first input of the first phase detector, the second input of which is connected to the first output of a tunable intermediate frequency generator, which is connected to the input of the second signal divider, the outputs of which are connected to the second fixed contacts of the fifth and the sixth switch, the first fixed contacts of which are interconnected, the movable contact of the fifth switch is connected to the output of the reference mixer, and the movable contact of the sixth switch is connected to the first input of the intermediate channel mixer of the reference channel, the second fixed contacts of the second and fourth, third and first switches are pairwise connected to each other, the first indicator input is connected to the output of the intermediate frequency mixer of the measuring channel, the second indicator input is connected to the output of the intermediate mixer the frequency of the reference channel, and the indicator output is connected to the resolver; an electronic switch, an adder, and phases are added a raster, a synchronous detector, a search generator control unit and a search generator; the output of the first phase locked loop mixer is additionally connected via a phase shifter to one of the inputs of the synchronous detector, the other input of which is connected to the first output of the tunable intermediate frequency generator, and the output of the synchronous detector is connected to the input of the search generator control unit, the second output of which is connected to the control input of the electronic switch, the first input of which is connected to the output house adder whose inputs are connected to outputs of the first and second phase detector, one input of the first oscillator swept frequency coupled to the output of the electronic switch, a second input coupled to an output of the search generator having an input coupled to the first output controlling unit search generator.

It is the introduction of the electronic switch, adder, phase shifter, synchronous detector, search generator control unit, search generator with appropriate connections that expands the functionality of the device.

The drawing shows a block diagram of the proposed device for measuring the amplitude-frequency and phase-frequency characteristics of quadrupoles with a frequency converter.

The device contains oscillators 1 and 2 of the oscillating frequency (GKCH 1 and GKCH 2), unit 3 of their control (CU), electronic switch 4 (EP), generator 5 of the receiver (CU), first divider b of signals (D1), attenuator 7 (At ), the first switch 8 (P1), the first mixer 9 phase-locked loop (S1 PLL), the adder 10 (5)). phase shifter 11 (p, second switch 12 (P2), third switch 13 (PZ), amplifier 14 (U), second mixer 15 phase locked loop (Cm2 PLL), first phase detector 16 (PD1), synchronous detector 17 (PD)) , search generator control unit 18 (SU), test quadrupole with frequency converter 19 (CX), reference mixer 20 (CMS), fourth switch 21 (P4), second phase detector 22 (FD2), tunable intermediate frequency generator 23 , fifth switch 24 (A5), second divider 25 signals (D2), sixth switch 26 (PB) , the mixer 27 of the intermediate frequency of the measuring channel (See IFR), the mixer 28 of the intermediate frequency of the reference channel (See FCF), the indicator 29 (I), the resolver 30 (RU), which are connected as follows.

The second control input of the first switchboard GKCH 1 and the control input of the second switchboard GCH 2 are connected to one of the outputs of control unit 3, the other output of which is connected to the input of a tunable intermediate frequency generator 23, the third output of which is connected to the second input of the second phase detector 22. Output of the first generator 1 the oscillating frequency is connected to the input of the first divider 6 signals and one of the inputs of the first mixer 9 of the phase-locked loop, the other input of which is connected to the output of the second switchboard 2, simultaneously connected to the second (g the heterodyne) inputs of the test quadrupole with a converter 19

frequency and reference mixer 20, the first input of which is connected to the movable contact of the third switch 13, the first fixed contact of which is connected to the first fixed contact of the fourth switch 21, the movable contact of which is connected to the output of the amplifier 14. whose input is connected to the movable contact of the first switch 8, the first fixed contact which through an attenuator 7 is connected to one of the outputs of the first divider 6 signals, the other output of which is connected to the first fixed contact of the second switch 12, the movable contact of which is connected to the first (signal) input of the tested quadrupole with a frequency converter 19, the output of which is connected to the first input of the intermediate frequency mixer 27 of the measuring channel, the second input of which is connected to the second input of the intermediate frequency mixer 28 and the second output of the tunable generator 23 intermediate frequencies, in turn, connected to the second input of the second mixer 15 phase-locked loop, the first input of which is connected to the output of the first mixer 9 phase-locked loop and the first input of the first phase detector 16, the second input of which is connected to the first output of the tunable intermediate frequency generator 23, additionally connected to the input of the second signal divider 25, the outputs of which are connected to the second fixed contacts of the fifth 24 and sixth 26 switches, the first fixed contacts of which are interconnected. The movable contact of the fifth switch 24 is connected to the output of the reference mixer 20, and the movable contact of the sixth switch 26 is connected to the first input of the mixer 28 of the intermediate frequency of the reference channel. The second fixed contacts of the second 12 and fourth 21, third 13 and first 8 switches are interconnected in pairs. The first input of the indicator 29 is connected to the output of the mixer 27 of the intermediate frequency of the measuring channel, the second input of the indicator 29 is connected to the output of the mixer 28 of the intermediate frequency of the reference channel, and the output of the indicator 29 is connected to the resolver 30. The output of the first mixer 9 of the phase-locked loop is additionally connected via the phase shifter 11c one of the inputs of the synchronous detector 17, the other input of which is connected to the first output of the tunable intermediate frequency generator 23, and the output of the synchronous detector 17 is connected with the input of the search generator control unit 18, the second output of which is connected to the control input of the electronic switch 4, the first

the input of which is connected to the output of the adder 10, the inputs of which are connected to the outputs of the first 16 and second 22 phase detectors. One of the inputs of the first oscillating frequency generator 1 is connected to the output of the electronic switch 4, the second input of which is connected to the output of the search generator 5, the input of which is connected to the first output of the search generator control unit 18.

Adder 10 is a scale amplifier included for summing input signals. The search generator 5 is a sawtooth generator that is activated by the control circuit 18. The electronic key 4 may be, for example, a pin-diode switch. The control circuit 18 is a two-output large-scale amplifier.

The device works as follows.

GKCH 1 and 2 Provide operation of the device in two modes: the variable mode of the first intermediate frequency at the output

test quadripole with frequency converter; the constant intermediate frequency mode at the output of a test quadripole with a frequency converter.

The mode of the first intermediate frequency variable at the output of the tested quadrupole with a frequency converter. When operating in this mode, the voltage from the control unit 3 establishes the initial difference between the frequency ol of the oscillator 1 of the oscillating frequency and the frequency 0) 2 of the oscillator 8 of the oscillating frequency, equal to the initial intermediate frequency of the band analysis of the tested quadrupole with a frequency converter. The same voltage sets the initial value of the first (variable) intermediate frequency CDs of the signals of the tunable generator 23 intermediate frequencies taken from its first output. Then, a sweep is activated relative to the oscillating frequency generator 2 tuned to the fixed frequency.

GCH 1 in the range equal to the analysis bandwidth of the first (variable) intermediate frequency of the test quadrupole with a frequency converter. In this case, synchronously with the oscillator 1 oscillating frequency

sweeps a tunable intermediate frequency generator 23 in a given range of the first (variable) intermediate frequency. At the same time, in the tunable intermediate frequency generator 23, auxiliary intermediate frequency signals are generated with an accuracy to the phase equal to

(0) 3 + Y)

where Q is a constant low intermediate frequency.

A part of the signals of the first (variable) intermediate frequency (the rear of the output of the first mixer 9 phase-locked loop is fed to one of the outputs of the mixer 15 of the phase locked loop, where it is mixed with the auxiliary frequency signal ((S3 + Q) from the tunable intermediate-frequency generator 23.

The resulting signal of the second low constant intermediate frequency Q from the output of the mixer 15 is fed to one of the inputs of the phase detector 22, which is compared with the reference signal QI generated in the tunable intermediate frequency generator 23 and removed from its third output. The result of the comparison with the output of the second phase detector 22 is fed to the input of the adder 10 of the signals, where its amplitude is added to the amplitude of the adjusting signal from the output of the first phase detector 16, the total control signal from the output of the adder 10 through the electronic switch 4 is fed to one of the inputs (for example, the first a) the first GKCH 1, controlling its frequency so that the difference between it and the frequency of the second GKC 2, up to a phase, is maintained equal to the current value of the first (variable) intermediate frequency o / s at the first in during the tunable generator 23 intermediate frequencies.

The mode of constant intermediate frequency at the output of the tested quadrupole with a frequency converter. When operating in this mode, the first 1 and second 2 GCUs are swept synchronously in the specified microwave range. The value of the first intermediate frequency is chosen by anyone in the working range of the tunable intermediate frequency generator 23 and during the sweep process remains constant. In this case, one input of the first mixer 9 of the phase frequency autorunner is fed a part of the signals with the output of the hopper 1 and 2, and

as a result of their mixing, the signal of the first variable intermediate frequency od from the output of the first mixer 9 of the phase-locked loop is fed to one of

inputs of the first phase detector 16, where it is compared with the reference signal of the first intermediate frequency, coming from the first output of the tunable intermediate frequency generator 23. Result

comparison, in the form of a control signal from the output of the first phase detector 16, is fed to the input of the signal adder 10, where, if necessary, it is summed with the control signal from the second phase detector 22 and through the electronic switch 4 is fed to one of the inputs (for example, the first) of the first cnc switch 1, controlling its frequency so that the frequency difference between the microwave signals from its output and the output of the second switchboard 2

is kept constant in the process of their joint sweep and equal to the selected first variable intermediate frequency of the Eyes. In this mode, the control signal from the second phase detector 22 is trimming. The signal of the first variable intermediate frequency in the device can be obtained in accordance with the expression

thirty

(four)

UJ3 SU1 ± (U2.

Suppose that a conversion takes place in this device when the first intermediate frequency is obtained as the difference between the input frequencies and the Y2 frequencies.

In the first and second modes of operation of the device, a variable signal of the first intermediate frequency can be obtained by the upper al-coz or lower OJ2 - CU1. ftjQ conversion. The upper transformation is the frequency of the signals from the first GCCH 1 is higher than the frequency of the GCh 2 signals by the value of the first variable intermediate frequency. Bottom transform

- the frequency of the signals of the second GKCH 2 is higher than the frequency of the signals of the first GKC 1 by the value of the first variable intermediate frequency.

The type of conversion is selected using a phase shifter 11 by setting it to one of two fixed values of + 90 ° or -90 °. Let the signal from the first GCH 1

55

(five)

Ul Um1 SinWit + yJl,

a from the second GKCH 2

(6)

U2 Um2 sin r 2t + pi. where the phase shift. Then, after the first conversion of the signals in the first mixer 9 of the phase-locked loop at its output, an intermediate frequency signal takes place, from Urr3 sln (-ftJ2) t + + -unit sin (When this signal is applied to the synchronous detector 17 and the reference signal Umo sin ( t where Umo is the amplitude value of the reference signal; (p2 is the phase shift of the reference signal, from the first output of the tunable intermediate frequency generator 23 the signal at the output of the synchronous detector 17 will be described by the following expression: UCD Um3Sln j (-y) 2) h) where UCD synchronous output signal gi is the conductivity of the nonlinear element of the synchronous detector under the influence of the first harmonic of the reference signal, 90 ° is the phase shift introduced by the phase shifter 10; (951 -) A is the phase of the signal of the first intermediate frequency c. From expression (1) for the formation of Af (the sign of the control voltage at the output of the synchronous detector 17 UCD changes. From the output of the synchronous detector 17, the control voltage, via the search generator control unit 18 controls the operation of the search generator 5 and the electronic switch 4.. Depending on the sign (+ or -) of the control voltage from the output of the synchronous detector 17, the search generator control unit 18 includes either the search generator 5 or the electronic key 4. If the sign of the control voltage from the output of the synchronous detector 17 is opposite to that selected using the phase shifter 11 to the conversion type, the search mode of the PLL systems is turned on. In this case the electronic switch 4 connects the input of the first GKCH 1 to the output of the search generator 5. The sawtooth voltage of the search generator 5 tunes the frequency of the signals of the first GCN 1 until the signal of the first variable intermediate frequency of the cGW arrives at the input of the synchronous detector 17 through the phase shifter 11, the phase shift of which corresponds to the selected type of conversion; 3 this moment the capture mode begins whereby the signal of the search generator control unit 18 is turned on by the search generator 5 and at the same time the amplitude of the sawtooth voltage corresponding to the capture moment is stored. The electronic switch 4 connects the input of the first GCCH 1 to the output of the adder 10 and the entire phase eutrost control system switches the first 16 and second 22 phase detectors into a frequency hold mode. Changing the phase shift, which the phase shifter 11 realizes by a fixed value (+90) or (-90 °). It is possible to change the type of conversion in the device. The measurement of the attenuation of the parasitic reception of the test quadrupole with frequency converter 19 is made relative to the ratio of its main reception channel. By means of a phase shifter 11, the main receiving channel of the tested quadrupole with a frequency converter 19 is turned on. Switches 8, 12, 13. 21 and 24 devices are set to position 1, and device switch 26 is set to position 2, Signal (1L from the first switchboard 1 is fed to the first (sig nal) input, q of the quadripole with frequency converter 19, where is converted by a signal with a frequency coz from the second GKCH 2 into the signal of the first (variable) intermediate frequency С (/ з. From the output of the tested quadrupole with the frequency converter 19) the signal of the first (variable) intermediate frequency is converted in the mixer of the intermediate frequencies of the measuring channel 27, the signal of a constant low intermediate frequency O. l is fed to the first input and, the chdikator 29, which is an indicator of the relationship between the amplitudes and phases of the input signals.The second input of this indicator 29 through the intermediate frequency mixer 28 gives the reference signal c frequency one from the first output of the tuned, generator 23 intermediate frequencies, also converted in the mixer 28 of the intermediate / common frequency of the reference channel into a signal of a constant low intermediate frequency Q,

The indicator 29 records the ratio of the amplitudes of the signals at its first and second inputs, and the result is stored in the resolver 30.

Then, using the phase shifter 11, a parasitic (mirror) reception channel of the test quadrupole with frequency converter 19 is established and the result of the amplitude ratio at the inputs of the indicator 29 is recorded again. Then this result is compared with previously stored in the resolver 30, which then calculates the amount of parasitic suppression reception channel relative to the main test quadripole with frequency converter 19

When measuring on the main and mirror reception channels, the reference signal at the second input of the indicator 29 from the tunable intermediate frequency generator 23 remains unchanged in frequency and amplitude, which ensures uniformity of measurements.

The measurement of the amplitude-frequency and phase-frequency characteristics in the device on the main type of conversion of the tested quadrupoles with a frequency converter is performed as follows. At the beginning, the electrical lengths of the measuring and reference channels of the device, as well as the path of the local oscillator at frequencies л, GJ2, and one after alignment, including the first and second dividers, are aligned, then the channels of the device are labeled so that the phase in the measuring channel was decreasing, and in the reference one - subtracted in this difference.

: At the end, the switches 8, 12, 13, 21, 24 and 26 are set to position 1, in which the phase difference measurement circuit is implemented. The signal from the first oscillator T oscillating frequency is divided by the first divider b into two channels: measuring and reference. The signal in the measuring channel.

Ui Umisln (a; it + 951)

(ten)

where Ui is the signal in the measuring channel; Umi signal amplitude value; - phase of the signal in the measuring channel on the first (signal) input of the quadrupole with a frequency converter. Signal in the reference channel

Ui U mistn (cyit-f- i) (11) where.and is the signal in the reference channel;

Umi - signal amplitude value;

p is the phase of the signal in the reference channel at the input of the reference mixer.

The signal of the measuring channel through the switch 12 is fed to the first input of the tested quadrupole with frequency converter 19, and the signal of the reference channel is connected via a serially connected attenuator 7 and amplifier 14 to the first input of the reference mixer 20, where it is converted into a signal using the signals from the second generator 2 the first variable frequency intermediate frequency, which then into the mixers of the intermediate frequency measuring 27 and the reference 28 channels, is converted into signals of a low constant between of the frequency Q, in turn, fed to the first (measuring) and second (reference) inputs of the indicator 29. Amplification of the amplifier 14 compensates for attenuation of the attenuator 7. Conversion of signals in the intermediate frequency of the measuring 27 and reference 28 channels by subtracting frequencies is performed using auxiliary intermediate frequency signals from the second generator output 23 variable intermediate frequencies .:.

At the output of the tested quadrupole with a frequency converter 19 after the conversion, a signal Uz takes place. equal

from Um3 sin (o -602) -t + + y i-iRz-f (12)

Umaslncrtst + r- + AyJi

/ -, - where and tz is the amplitude value of the signal;

A I-phase shift of the test quadripole with a frequency converter.

At the output of the reference mixer 20 after the conversion, there is a signal Kz, equal to

U3 Um3Sln ((yi- (W3) t +

-r + Lu52 Um3 sin + + +,

where Um3 is the amplitude value of the signal;

p is the phase of the first oscillating frequency generator 1;

ph is the phase of the second oscillating frequency generator 2;

 phase shift attenuator 7;

Auzz-phase shift amplifier 14; B. (P / - phase shift of the reference mixer 20.

Assuming that the amplitude-frequency and phase-frequency characteristics of mixers 27 and 28 are identical, and the electrical lengths of the channels are equal, the result of comparing the phase difference in the indicator can be represented as

(U3U3) (95i- + - (14) -) (- Ay -),

where A is the measured difference in degrees, taking into account the sign,

K - coefficient of proportionality;

Kf (out, out) is a function implemented by a phase detector,

This result enters solver 30, where it is remembered.

In position 2 switches 8, 12; 13, 21, 24 and 26 a circuit is implemented to measure the sum of the phase shifts of the reference mixer 20 and the test quadripole with a frequency converter 19. The signal of the first variable intermediate frequency to3 from the first output of the tunable intermediate frequency generator 23 by the second signal divider 25 is divided into channels: auxiliary and reference. Here, the reference mixer 20 and the test quadrupole with a frequency converter 19 are connected in series.

An auxiliary channel signal is supplied to the intermediate frequency output connector of the reference mixer 20.

from sin (ftiGt), (15) where is the signal phase and the intermediate frequency connector of the reference mixer. After the inverse transformation in the reference mixer 20, the signal Ul Uni1 81п (й; з + С02) t -I + У5з + Д рЗ: 1А 4-1-) takes place on its first input connector. This signal is fed to the input of the tested quadrupole with frequency converter 19 is being transformed, with the result that there is a signal at its output

from Umb sin (u) 3 + ftJa - od) t H- (rg - + -b A -b

(17)) Um3 sin (-f- (pz -f + A +),

where v "pi are the phases of the signals in the heterodyne channels of the reference mixer and the test quadrupole, which for equal electrical path lengths mutually compensate.

This signal is then fed through the intermediate-frequency mixer 27 of the measuring channel to the first input of the indicator 29, to the second input of which, through the intermediate-frequency mixer 28, the reference signal Uz comes from the output of the second divider 25 signals

, (uJ3t-t-). (18)

Given that the indicator 29 determines the phase difference between the first and second channels, it will fix the sum of the phase shifts of the reference mixer 20 and the test quadrupole with frequency converter 19

In Kf (U3, U3) -N

(19) + A951 + A C-J-A o -v

where RE v (p3 - with equal electric lengths of the channels are mutually destroyed

Solver 30, after entering into it the sum of shifts of phases B, produces a solution of the system of equations and

calculating the phase shift of the test quadripole with frequency converter 19 in the following sequence A — Auz-A 4; In A + A, taking into account the signs. The amplitude-frequency characteristic of the tested quadrupole with a frequency converter can be measured in the first position of the switches 8, 12, 13, 21, 24 and 26 by comparing it with the similar characteristic of the reference mixer 20. The technical and economic advantage of the proposed device is comparable to

Claims (1)

Claim A device for measuring the amplitude-frequency and phase-frequency characteristics of a four-terminal network with a frequency converter, containing two oscillating frequency generators, the first control inputs of which are connected to the first and second inputs of the control unit, the third output of which is connected to the input of the tunable intermediate frequency generator, the third output of which is connected to the second input of the second phase detector, the output of the first oscillating frequency generator is connected to the input of the first signal splitter and one of the inputs of the first a phase locked loop, the other input of which is connected to the output of the second oscillating frequency generator, connected to the heterodyne inputs of the tested quadripole with a frequency converter and a reference mixer, the first input of which is connected to the movable contact of the third switch, the first fixed contact of which is connected to the first fixed contact of the fourth switch the movable contact of which is connected to the output of the amplifier, the input of which is connected to the movable contact of the first switch I, the first fixed contact of which through the attenuator is connected to one of the outputs of the first signal splitter, the other output of which is connected to the first fixed contact of the second switch, the movable contact of which is connected to the first (signal) input of the tested four-terminal with a frequency converter, the output of which is connected to the first input the mixer of the intermediate frequency of the measuring channel, the second input of which is connected to the second input of the mixer of the intermediate frequency of the reference channel and the second output of the tuning removable intermediate frequency generator, in turn, connected to the second input of the second phase locked loop, the first input of which is connected to the output of the first phase locked loop and the first input of the first phase detector, the second input of which is connected to the first output of the tunable intermediate frequency generator, which is connected with the input of the second signal divider, the outputs of which are connected to the second fixed contacts of the fifth and sixth switches, the first fixed contacts which are interconnected, the movable contact of the fifth switch is connected to the output of the reference mixer, and the movable contact of the sixth switch is connected to the first input of the mixer of the intermediate frequency of the reference channel, the second fixed contacts of the second and fourth, third and first switches are paired between the robe, the first input of the indicator is connected with the output of the mixer of the intermediate frequency of the measuring channel, the second input of the indicator is connected to the output of the mixer of the intermediate frequency of the reference channel, and the output the indicator is connected to a deciding device, characterized in that, in order to expand the functionality, an electronic switch, an adder, a phase shifter, a synchronous detector, a search generator control unit and a search generator are introduced into it, while the output of the first phase-locked loop is additionally connected via phase shifter with one of the inputs of the synchronous detector, the other input of which is connected to the first output of the tunable intermediate frequency generator, and the output of the synchronous detector with is dined with the input of the search generator control unit, the second output of which is connected to the control input of the electronic switch, the first input of which is connected to the output of the adder, the inputs of which are connected to the outputs of the first and second phase detector, one of the inputs of the first oscillating frequency generator is connected to the output of the electronic switch, the second input of which is connected to the output of the search generator, the input of which is connected to the first output of the control unit of the search generator. • Compiled by K. Korotkov Editor Y. Sereda Tehred M. Morgenthal Corrector S. Cherni Order 423 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries at the State Committee for Science and Technology 113035, Moscow, Zh-35. Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.