SU890264A1 - Four terminal network phase shift meter - Google Patents

Description

The invention relates to microwave measurement technology and can be used to measure linear reciprocal and non-reciprocal quadripoles. An automatic non-reciprocal phase shift meter for quadrupoles is known, which includes a oscillating frequency generator, a modulator, a ferrite valve, a combined double tee, matched load, a quadrupole under study, two detectors, two subtraction circuits, a DC amplifier, a ratio amplifier, a synchronous detector, an electron beam indicator, sawtooth generator and saw voltage generator 1. However, in the known meter, there is an additional measurement error due to First of all, enna is the nonidentity of the parameters of the combined / joining tee and their dependence on the magnitude of the measured phase shift. The calibration process of the meter is associated with a relatively large amount of time, since it involves the calibration of a waveguide in the measuring path instead of the quadrupole under study. In addition, this meter does not allow measurements of forward and reverse phase shifts of the studied quadrupole. The closest in technical essence to the present invention is a phase shift meter for reciprocating quadrupoles containing a high-power microwave generator, first and second ferrite valves, a power divider, first and second directional couplers, oriented to waves incident on the quadrupole, first and second directional couplers oriented to the waves passing through a quadrupole, the first, second, third, fourth high-frequency switches, the test non-reciprocal two-terminal, the first and second tees, quadrature and antiphase eight-pole, first, second, third, fourth inertial high power meters, first, second, third, fourth matched loads, first and second subtraction circuits, first and second synchronous detectors, first and second indicators with iryl in the middle of the scale, a CRT modulator, the output of the high-power microwave generator is connected to the input of the power divider, and the input to the first output of the modulator, the first and second outputs of the power divider sequentially through the first and second ferrite valves, the main channels of the first, second and fourth, third directional couplers respectively are connected to the first flange connections of the first and second high-frequency switches, the second flange connections of which are connected respectively to the input and output of the calibration channel, and the third to the input and the output of the test non-reciprocal quadrupole. The second flange connections of the third and fourth high-frequency switches are connected to the secondary channels of the first and third directional couplers, the third channels of the second and fourth directional couplers are connected to the third flange connections, and the first and second tees are connected to the first, respectively. The first and second quadrature (90 °) and antiphase (180 °) eight-port inputs are connected to the first and second outputs of the first and second tees, and the first and second outputs, respectively, through the first, second and third, fourth bezineeriojioifflbie power meters are connected to the first, second and the third, fourth agreed loads. The first and second inputs of the first and second subtraction circuits are connected respectively to the outputs of the first, second and third, fourth instantaneous power meters, and the outputs respectively to the horizontal and vertical deflection plates of the cathode ray tube, as well as to the first inputs of the first and second synchronous detectors , to the second inputs of which the second output of the modulator is connected. The outputs of the first and second synchronous detectors are connected to the inputs of the first and second indicators with a zero in the middle of the scale 2. However, there are additional errors in measuring phase shifts in the meter, the reasons for which are the existence of two simultaneously and oppositely directed microwave waves in the ring measuring path, non-identity of synchronous detectors and indicators with zero in the middle of the scale, finite isolation between the channels, presence of the microwave signal from the inputs and outputs of high-frequency switches and losses in them. The meter allows for panoramic playback: phase shifting in the frequency range, and, moreover, it is intended only to measure the phase shifts of non-reciprocal four points payers. The aim of the invention is to improve the measurement accuracy of forward, reverse and non-reciprocal phase shifts, the possibility of panoramic reproduction of phase shifts in the frequency range, as well as the possibility of measuring the phase shift of reciprocal quadrupoles. This goal is achieved by the fact that the quadrupole phase shift meter containing the modulator, the first and second ferrite valves, KOTOpi ix outputs, respectively, through the first and second, third and fourth directional couplers are connected to the inputs of the first and second microwave switches, to the first outputs which are connected to connect the waveguide segment, and to the second - the tested quadrupole, the first quadrature quadrupole, the first and second subtractors, the synchronous detector and the electron beam receiver, are entered oscillator frequency, additional microwave switch, second quadrature eight-port, first, second, third and fourth detectors, first and second electronic switches, analog-to-digital converter, memory block, digital-analog converter, arithmetic unit, digital indicator and control unit, the input of the oscillating frequency is connected to the output of the modulator, and the first output is connected to the input of an additional microwave switch, the first and second outputs of which are connected to the first and second ferrite wires In these cases, the first and second inputs of the first and second quadrature quadrupoles are connected respectively to the outputs of the first and third, second and fourth directional taps, and their first and second outputs through the first and second, third and fourth detectors are to the first and second inputs of the first and the second counters, the first and second inputs of the first electronic switch are connected to the outputs of the specified subtractors, and the output is connected to the first input of the synchronous detector, the second input of which is connected to the output of the modulator, with this The input of the analog-digital converter is connected to the output of a synchronous detector, and the output is connected via a serially connected memory block and an arithmetic unit to the inputs of a digital indicator and a digital-analog converter, the first and second inputs of the second electronic switch are connected respectively to the outputs of the digital-analog converter and synchronous the detector, and the output is with vertically deflecting plates of the electron-beam tube, with horizontally deviating KSHIMN plates which are sos; The oscillating frequency tori, and the first, second, third, and fourth outputs of the control unit are connected to the control inputs of the additional microwave switch, the first and second electronic switches, and the arithmetic unit.

The drawing shows the structural scheme of the proposed meter.

The meter contains a generator of 1 kachayunkky frequency. modulator 2, microwave switch first 4 and second 5 ferrite valves, first 6, second 7, third 8, fourth 9 directional coders, first 10 and second 11 microwave switches, waveguide length 12, follower FI IV quadrupole 13, first 14 and second 15 quadrature quadrupoles, first 16, second 17, third 18, fourth 19 detectors, first 20 and second 21 subtractors, first 22 and second 23 two-channel electronic switches, synchronous detector 24, digital-analog converter 25, CRT 26, analog-to-digital converter 27 , memory block 2b, arithmetic cue unit 29, the digital indicator 30 and a control unit 31.

The meter operates as follows. In calibration, switches 10 and 11 are set to the first position, the oscillating frequency generator 1 and control unit 31 are switched to manual mode, the frequency of the microwave signal is set to the average operating frequency of the four-port circuit, and 31 control is set in such a position that the first output of the controlled microwave switch 3 is connected to the ring measuring path, the output of the subtractor 20 a is connected to the input of the synchronous detector 24 to the output - vertically deflecting plates of a CRT 26. With such a suck; And the microwave signal meter comes from the oscillating frequency generator 1 to the input of the switch 3 and from the first output it passes the ferrite valve 4 in series, the directional couplers 6 and 7, the path section, the directional couplers 8 and 9 and is absorbed by the ferrite valve 5. On the first and second input1 quadrature quadrupole signals receive microwave signals from the outputs of the secondary channels of the first 6 and third 8 directional couplers (since they are oriented to the feed wave)

and, Asinwt; (1)

U2 BsinCwt + s), (2)

where a and b are the amplitudes of the microwave signals;

 - phase shift of the waveguide segment.

)

1: sl11 detectors 16 and 17 are square 1CH, the video signals at their outputs are equal

J and „- A + - B - -ABsin, (3)

one

I -I ..

Un - A + - 8 + ABsinip,

(four)

The output of the subtractor 20 has a signal equal to the difference of these two video signals.

and and ,, - and, b 2ABsinvJ. (5)

By adjusting the phase response, its reading of the digital indicator 30 is set to zero.

Calibration of the meter to measure reverse phase shifts is similar, but with the help of the microwave switch 3 the direction of propagation of the microwave is changed

waves in the ring path to the reverse, to the input of the synchronous detector 24 is connected via an electronic switch 22, the output of the subtractor 21.

In the mode of measuring the phase shifts of the microwave

the switches 10 and 11 are shifted to the second position, the control unit 31 and the oscillating frequency generator 1 are switched to automatic mode. In this case, at each moment of measurement, the oscillating frequency generator 1 is automatically stopped for oscillation frequency, as a result of which, for example, when measuring phase shifts of reciprocal quadrupoles, it is possible to observe forward, reverse, and nonreciprocal four-pole phase shifts.

Consider the process of measuring phase shifts and at the same time show the realization of the possibility of measuring phase shifts of both reciprocal and non-reciprocal quadrupoles, as well as increasing the measurement accuracy. In the phase shift measurement mode ujaHMHoro of the quadrupole, the switches Yu and 11 are set to the second position, the control unit 31 is transferred to the manual mode, the first output of the microwave switch 3 is connected to the ring measuring path, the reader 20 output is connected to the input of the synchronous detector 24, and the subtractor 20 is connected to the input, and - vertically deflecting plates of a CRT 26. In this case, a video signal is supplied to the input of the synchronous detector 24, the output of which is taken from a constant voltage proportional to the measured four-phase shift lusnika This voltage is displayed on a CRT screen as a function of two

coordinates: along the y axis, the deflection of the beam is proportional to the measured phase shift, and along the X axis is proportional to the frequency of the microwave signal. Then, according to the signal from control unit 31, the oscillator 1 of the oscillating frequency is tuned to a new frequency, and the measurement process is repeated. After the end of one sweep period on the tube screen, we obtain a set of points y (f). The constant voltage from the output of the synchronous detector 2 also goes to analog-to-digital converter 27, from the output of which the voltage in digital form goes to digital indicator 30. The measurement of direct and inverse phase shifts of non-reciprocal quadrupoles takes place similarly to the measurement of phase shift of four-pole} , but in this case the voltage is digitally generated from the output of the analog-digital converter 27, proportional to tf and (fg, are stored by the memory block 28. In the measurement mode of non-reciprocal phase sd The control unit receives a signal to the memory unit 28, which supplies a voltage proportional to (p and ip g, to the arithmetic unit 29. At the same time, control unit 3 receives a signal to the electronic switch 23, which is connected to the vertical deflection plates of the CRT 26 output of a digital-analog converter 25. From the output of the arithmetic unit 29, a voltage equal to / (f - (f - (fg, is fed to the input of the digital-analog converter 25 from the output of which voltage is supplied in analog form to vertical-deflection plates CRT 26.

Measurement operations ggp and are carried out sequentially according to commands from control unit 31. As a result, dependencies are displayed on the screen of the CRT 26: f

 ri (f); vogp. 72 (f); AY 73 (0.

If we assume that in the measurement mode V5 the path is recorded simultaneously from both the valve 4 side and the valve 5 side, then the coupler 6, due to its final directivity, receives part of the microwave signal of the return wave passing through the path section, and the coupler 8 the part of the microwave signal of the return wave and the part of this signal reflected from the output of the quadrupole, to which this coupler is turned on in the forward direction. Therefore, an additional measurement error f arises, due to the fact that the signal from the output of the secondary channel of the directional coupler 6 is removed

Uj Asinwt -L S sin (ojt -I-ip {-) „and the signal from the output of the secondary channel of the directional coupler 8 is removed.

Uj In sin (cot + „„) Е sinojt + + D sin (ojt -t-).

Claims (2)

1. Elizarov A. S. Automating the measurement of the parameters of linear nonreciprocal microwave frequencies quadripoles. M., Soviet Radio, 1978. 2. USSR author's certificate number 363043, cl. G 01 R 25/00, 1973.