SU777595A1 - Device for monitoring deviations of differential phase shifts - Google Patents

Description

frequency control connected to the reference crystal oscillator and the local oscillator, and to the input of the model phase shifter, and the output of the second mixer is connected to the input of the second intermediate frequency amplifier, the other input of which is connected to the sample attenuator and the output to the phase detectors connected to the phase corrector via phase shifters with a control unit, the input of which is connected to the modulator, and the output to the motors 3.

The disadvantage of the prototype lies in the fact that the compensation of the measured parameters is carried out using electromechanical automatic control systems, where the processing of the error of the error occurs with the help of motors mechanically moving the model phase shifters and attenuator, respectively. Due to the inertia of these systems, the meter performance is limited and is usually of the order of seconds. With high seriality of the tested products, the time for their testing is unacceptably increased. In addition, the known device does not have a software switch of phase shifts with measurement of residual (uncompensated) error, which leads to a significant increase in measurement error with an increase in the measured phase shift (about 7 ° with a controlled shift of 360 °).

The purpose of the invention is to increase the speed and accuracy of control.

The goal is achieved by the fact that the device for controlling the deviations of differential phase shifts, contains a microwave generator, the output of which is connected to the inputs of the first and second mixers, the outputs of which are connected through the intermediate frequency amplifiers to the first inputs of the third and fourth mixers, respectively, a phase meter and a reference frequency generator , the first output of which is connected to the control input of the microwave generator, a block for entering the specified phase shifts, two frequency dividers, two frequency shift blocks, Phase shift compensation limiter and serially connected nosal amplifier, mixer and limiter, the second output of the reference frequency generator connected to the first inputs of the frequency dividers and the first frequency offset unit, the output of which is connected to the first input of the second frequency offset unit and the heterodyne inputs of the third and fourth mixers, the outputs of which are connected to the inputs of the band amplifier. The output of the input unit of the specified phase shifts is connected to the second input of the first frequency divider, the output of which is connected to the input of the reference channel of the phase meter, the signal input of which is connected to the output of the limiter.

The output of the phase meter is connected to the input of the distributor for compensation of phase shifts, the outputs of which are connected to the control inputs of the frequency dividers. The intermediate and main outputs of the second frequency splitter are connected to the second inputs of the first and second frequency offset blocks, respectively. The drawing shows a structural electrical circuit of the device.

The diagram shows a two-frequency microwave generator 1, the object under study 2, the equivalent of 3, mixers 4-7, intermediate frequency amplifiers 8, 9, generator

reference frequency 10, bandpass amplifier 11, mixer 12, limiter 13, phase meter 14, frequency offset blocks 15, 16, frequency dividers 17, 18, unit for inputting specified phase shifts 19, phase shift compensation distributor 20.

A device for monitoring the deviation of the differential phase shifts operates as follows. The signal from the first output of the microwave generator through the test

Object 2 and equivalent 3 are fed to mixers 4 and 5. Amplified by identical intermediate-frequency amplifiers 8, 9 to the magnitude required for the second conversion, the signals of the first intermediate

the frequencies are fed to mixers 6 and 7. The signals from the frequency offset blocks 15 and 16 are received at the heterodyne inputs of the same mixers. The input of the frequency offset block 15 is connected to the output of the reference frequency generator 10 and passed through the output frequency splitter 18. The inputs of the frequency offset block 16 are connected with the output of the frequency offset unit 15 and the main output of the divider

frequency 18. The signal from the second output of generator 1 is fed to mixers 4 and 5 to form a signal of the first intermediate frequency. The control input of the dual-frequency generator 1 is connected to the output

reference frequency generator 10.

The signals of the second intermediate frequencies through the bandpass amplifier 11 are fed to the mixer 12, from the output of which the low-frequency signal through the limiter 13 enters the trigger input of the phase meter 14. The channel of the reference signal of this phase meter is connected to the output of the frequency divider 17, the input of which is connected to the reference frequency generator ten.

The output of the phase meter 14 is connected via the compensation distributor 20 to the control inputs of the frequency dividers 17 and 18. The second input of the frequency divider 17 is connected to the output of the setpoint phase input unit

shifts 19. The frequency of the signals from the outputs of mixers 4 and 5, carrying information about the phase shift of the object under study, is equal to the frequency fo of the generator 10. The frequency of this signal is shifted by F,

equal to the frequency of the intermediate output

frequency divider 18. Thus, the frequency of the signal from the output of this block is equal to fo + FILI / o- -f-. Bq. to the second block, see frequency 16, this frequency is additionally shifted by A.F, equal to the frequency from the main output of frequency divider 18. Therefore, heterodyne signals to mixers 6, 7 differ in frequency by D / -, which is much lower than frequency F.

The signals after the outputs of the frequency mixers F and / -f AF (F-AF) are amplified by a common bandpass amplifier and are shifted at its output in mixer 12. Thus, information is transferred about the phase shift under study and the low fixed frequency Af. The reference signal is formed by a divider 17 with a division factor equal to the division factor of the frequency divider 18. In the trigger phase meter 14, the phase shift is converted into a time interval. Thus, a pulse from the output of the phase meter, equivalent in duration to the initial phase shift of the object under study (initial electrical length), through the compensation distributor 20, depending on the sign of the phase shift, enters the division delay in frequency dividers 18 and 17, compensating the initial phase shift with an accuracy of discrete value of 360 °. ,

where n is the division factor of the frequency divider.

The compensated value is remembered by dividers until an external command arrives, leading them to the initial state. Thus, the subsequent measurement of phase shifts is made from the initial phase shift level, i.e., differential phase shifts are measured. To measure the deviations of these shifts from the specified values, a phase shift equal to the specified one is entered using the input unit of the specified phase shifts 19 into the frequency divider 17, producing a dividing delay by the specified value.

The increase in accuracy is achieved by the fact that the frequency stability of all signals starting from the first intermediate frequency is determined by one reference frequency generator, and by the fact that the main amplification of the signals is produced by a common bandpass amplifier 11, which allows to reduce the error due to its phase instability by a factor of where AF is a band

D

bandwidth amplifier. All compensation and phase shift control nodes operate at fixed frequencies. The setting of phase shifts occurs with high accuracy, since the division delay is always equal to the integer part of the low frequency oscillation period .:

Transfer of information; : rb amplitude and phase parameters of the devices under study for a fixed stable intermediate frequency are proposed. The device provides them with practical measurements in any part of the microwave range.

In this device, the control of the phase shift of the reference signal is carried out electronically by controlling the frequency division ratio of the signal included in the second local oscillator, which greatly increases the speed of the device, and also allows you to switch the phase shift of the reference signal from

greater degree of accuracy with a resolution of 360/2, where l is any positive number.

This device can be used in installations with software

control, which will allow automating the entire cycle of control of parameters of controlled phase shifters under the conditions of serial and mass production.

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Claims (3)

Invention Formula A device for monitoring differential phase shift deviations, comprising a microwave generator, the output of which is connected to the inputs of the first and second mixers, the outputs of which are connected via the intermediate frequency amplifiers to the first inputs of the third and fourth mixers, respectively, a phase meter and a generator the reference frequency, the first output of which is connected to the control input of the microwave generator, characterized in that, in order to increase speed and control accuracy, an input block is inserted into it specified phase shifts, two frequency dividers, two frequency offset blocks, a phase shift compensation distributor and serially connected bandpass amplifier, a mixer and a limiter, the second output of the reference frequency generator connected to the first inputs of the frequency dividers and the first frequency offset block whose output is connected to the first the input of the second frequency offset unit and the heterodyne inputs of the third and fourth mixers, the outputs of which are connected to the inputs of a bandpass amplifier, the output of the input unit specified x phase shifters connected to the second input of the first frequency divider, whose output is connected to the input of reference channel phase meter, the signal input of which is connected to the output of the limiter, the output of the phase meter is connected to the input of the distributor compensation phase shifts, the outputs of which are connected to the control inputs of the frequency dividers, the intermediate and main outputs of the second frequency divider are connected to the second inputs respectively of the first and second frequency offset units. Sources of information, pryi 1e in view of the examination 1. USSR author's certificate number 467295, cl. G OliR 2.5 / 04, 1973. 2. USSR Certificate of Arthur No. 519652, cl. Q 01R 27/28, 1974. 3. Technical description MG2, 739.000 (prototype).