SU1539683A1 - Device for automatic monitoring of amplitude and frequency characteristics - Google Patents

Abstract

The invention can be used to automatically control the parameters of communications equipment and electronic devices. The purpose of the invention is to increase the sensitivity and noise immunity of automatic measurements of the parameters of the amplitude-frequency characteristic achieved by making adjustments to a sufficiently large input signal level, which eliminates the possibility of a false adjustment to the noise signal. For this, the device includes a switch 4, a tunable preselector 5, a signal maximum meter 8, a synchronization unit 11 and a tuning control unit 13. The device automatically measures the relative method of the transmission coefficient of the quadrupole 14 under investigation at a discrete set of frequencies in the range specified by the frequency control unit 12 and tunable generator 3, after presetting at each frequency point of the tunable preselector 5. , the intermediate frequency signal converter 7 and the signal processing unit 9 are supplied to the registration and display unit 10. The tested quadrupole is connected to the input of the device using terminals 1 and 2. The tuning control block 13 contains a logic element as well as a series-connected pulse generator, a logic gate, a pulse counter, a D / A converter and a scale converter. 2 Il.

Description

1

The invention relates to a measurement technique, in particular, to means for automatically controlling parameters of communication means, radioelectronic equipment, and the like.

The aim of the invention is to increase the sensitivity and noise immunity of automatic measurements of the parameters of the amplitude-frequency characteristic by adjusting to a sufficiently large input signal level, which eliminates the possibility of a false adjustment to the noise signal.

FIG. 1 shows the block diagram of the device; in fig. 2 - tuning control unit.

The device contains input 1 and output 2 terminals, tunable generator 3, switch 4, tuned 2 preselector 5, mixer 6, intermediate frequency signal converter 7, signal maximum meter 8, signal processing unit 9, recording and display unit 10, unit 11 2 synchronization, frequency control unit 12, tuning control unit 13, quadrupole under study 14. At the same time, the output of the quadrupole under study 14 is connected through a series-connected 3 switch 4, tunable preselector 5, mixer 6, The intermediate frequency signal carrier 7, the signal maximum meter 8 and the signal processing unit 9 are connected to the input of the recording and display unit 10. The output of the synchronization unit 11 is connected to the corresponding inputs of the frequency control unit 12, the switch 4, the setup control unit 13, the maximum meter 8 and the recording and display unit 10. The tuning control unit 13 comprises a logic element 15, as well as a series-connected pulse generator 16, a logic gate 17, a pulse counter 18, a digital-to-analog converter 19 and a scale converter 20, the output of which is the output of block 13..

The principle of control of the frequency response of the proposed device h is the measurement of the transmission coefficients of the studied quadrupole 14 at a discrete set of frequencies overlapping a given frequency range. The range information is contained in the memory element of the frequency control unit 12, for example in the form of initial codes,

finite frequency range and scanning resolution (number of frequency points). The synchronization unit 11 issues, at equal time intervals, the duration of which is determined by the measurement time at any frequency, sets of commands (signals) over which measurement operations are performed, the same for all frequency points.

When measuring at any frequency (for example, F.) of a given range, the device operates as follows.

The synchronization unit 11 sends to the second input of the control unit 12 often the command Setting the frequency by which the unit 12 sets and maintains at the corresponding generator outputs 3 the frequency F, the signal and the frequency of the local oscillator shifted by O1 relative to the frequency F by the value of the intermediate frequency.

Simultaneously with the command Setting the frequency to the control input of the switch 4, the state 1 command is given, the third output of the control unit 12 is given, the frequency to the second control input of the preselector 5 is given to the subband number command. By command State 1, the switch is set to a state in which the input signal of preselector 5 is fed to the input signal of a quadrupole under study 14. By command number of the subband, the frequency subband of Preselector 5 is turned on, which contains frequency F.. For the implementation of the Set frequency command, a period of time is chosen that is known to be sufficient for setting the frequency at any frequency point. After the end of the specified time interval, the synchronization unit 11 sends the Setup command to the first input of the configuration control unit 13 and the Record command to the control input of the maximum signal meter 8. On the Adjustment command, which arrives at the logic element 15 of the adjustment control unit 13, the output of the logic circuit 15 generates signals, on which the counter 18 is reset and the logic gate 17 opens, which ensures the passage of pulses from the generator 16 output to the counter input of the counter 18. At the output a digital-to-analog converter 19, an increasing voltage is generated corresponding to the growing digital code at the output of the counter 18.

nor, obviously, sufficient for tuning preselector 5 at any frequency point.

After the specified period of time has expired, the synchronization unit 1I sends to the control input of the switch 4 a state 2 command to switch the switch 4 to a state Q in which the output signal of the quadripole 14 is being input to the input of the configured preselector 5. the second state at the first 15th input of the signal processing unit 9 is the voltage U of the converted output signal of the quadrupole 14 at this frequency, and at the second input is the voltage U0, the ratio 6, etc. 7 the forming-on signals 20 sponds to the four-input input ny 8 meter maximum signa- rehpolyusnika. By final measurement. Registration team, which

Upon the Record command, the meter 8 is supplied to the third input of the block 10. Through the converter of the scale 20, the indicated voltage at the scale required to implement this tuning subband is fed to the first control input of the selector 5, the voltage on which determines the position of the center frequency bandwidth. preselector. Thus, with the command Tuning, the dental frequency FO of the passband of the preselector 5 is scanned, starting with some initial frequency of the tuning subband containing the frequency F. of the input signal of the preselector 5. As the FO frequency approaches the frequency F. The output level of the preselector 5 increases, entering through the mixture

starts tracking the level of its own input voltage, which increases during the setup process. At the moment of transition of this level through the maximum value, the meter 8 forms at the second output a signal arriving at the second input of the control unit 13 of the control 30. In this case, the first output of the meter 8 records the maximum value U0 of the level of its input voltage. The moment of occurrence of the signal of transition through a maximum corresponds to the Soviet-35 measurement of the transmission coefficient

and f

those. end

frequency drop

setting. By this signal, the logic element 15 of the tuning control unit 13 closes the valve 17, stopping the flow of pulses to the counting input of the counter 18, which fixes the voltage at the output of the tuning control unit 13 supplied to the first control input of the selector 5. Thus, the tuning of the preselector 5 is fixed at the frequency F. of the input signal until the end of the measurement at this frequency. Thus, after the adjustment to the second input of the signal processing unit 9 from the second output of the signal maximum meter 8, the voltage U0, corresponding to the input signal of the quadrupole 14, passes through the adjusted measurement-converted channel. Voltage U0 is a reference for calculating the transfer factor of a quadrupole. The time span is selected for the implementation of the Setup command.

40

the quadrupole after presetting at each frequency point of the specified range, and the tuning is carried out by a sufficiently large input signal of the quadrupole, which simplifies the tuning process and makes it more reliable, because eliminates the possibility of false settings for signal interference.

45

Due to the fact that the output signal of the quadrupole is fed to the input of the mixer after the selective amplifier, the lower limit of the voltage measured

50 signals, respectively, decreases, thus increasing the allowable level of interference from the mirror frequency channel and other interfering signals. In addition, to implement the relative method of controlling the frequency response of the device in question, it is not necessary to create two identical measuring channels, the non-resident of which worsens the measurement accuracy.

registration and indication, the registration (memorization) and display of the UC / U0 value generated in the signal processing unit 9, representing the transmission coefficient of the four-port network 14 at a given frequency, occurs. In the following frequency points, the measurement process, starting with the command Setting the frequency of the synchronization unit 11, proceeds similarly.

The device performs automatic

the quadrupole after presetting at each frequency point of the specified range, and the tuning is carried out by a sufficiently large input signal of the quadrupole, which simplifies the tuning process and makes it more reliable, because eliminates the possibility of false settings for signal interference.

Due to the fact that the output signal of the quadrupole is fed to the input of the mixer after the selective amplifier, the lower limit of the voltage measured

signals, respectively, decreases, thus increasing the allowable level of interference from the mirror frequency channel and other interfering signals. In addition, to implement the relative method of controlling the frequency response of the device in question, it is not necessary to create two identical measuring channels, the non-residents of which degrade the accuracy of the measurements.

Claims (1)

Invention Formula A device for automatic control of amplitude-frequency characteristics containing a tunable generator, a signal output connected to the output terminal of the device, a mixer whose output through an intermediate frequency signal converter is connected to the first input of the signal processing unit, and a heterodyne input to the corresponding output of the tunable generator , the recording and display unit, the first input of which is connected to the output of the signal processing unit, and the second input - to the first output of the control unit rangefinders, the second output of which is connected to a control input perestraiva- emogo generator, the control output of which is connected to the first input of the frequency control unit, characterized in that, in order to increase the sensitivity and noise-resistance measuring circuit of the amplitude-frequency parameters From block 11 From measure / ff 8 maximum sync Fa G. 2 Editor M. Tsitkina Compiled by N. Mikhalev Tehred M. Khodanych Order 215 Circulation 540 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 characteristics, it includes a switch, a tunable preselector, a signal maximum meter, a tuning control unit and a synchronization unit, the output of which is connected to the first input of the tuning control unit, to the second input of the recording and display unit, the second input of the frequency control unit and the control inputs of the switch and the maximum signal meter, the first output of which is connected to the second input of the signal processing unit, the signal input to the output of the intermediate frequency signal converter, and the second output - to the second input of the control unit for tuning, the output of which is connected to the first control input of the tunable preselector, the second control input of which is connected to the third output of the control unit frequency, the output to the input of the mixer, and the signal input to the output of the switch, the first and the second inputs of which are connected respectively to the output and input terminals of the device. Kprese ek- mopj / 5 Proofreader N.Korol Subscription