SU555348A1 - Structural Correlation Voltmeter - Google Patents

Description

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The invention is for pawMonsMepvitelnoy technology and can be used for noise-proof measurement of the amplitude of 1-armature1crc s-channels in a wide frequency range,

The known Vaimnokorrel shunny HSNfegel amplitude of the harmonic signal is based on the measurement of the envelope values of the mutual correlation function of the detected and reference signals.

The disadvantage of the known meter is the necessity to harmonize the frequency of the reference signal with the frequency of the measured signal.

Also known is the structural-correlating scan meter, based on measuring the value of the autocorrelation function of a signal at a certain delay, it can be measured both by an analog autocorrelation function and by a reverse autocorrelation function, and containing an indicator and a channel an autocorrelation meter in which delay lines, multiplier and integrator are sequentially included.

A disadvantage of such meters is the need to match the delay value with the frequency of the input rms. Since, for example, the values of the relay autocorrelation function are proportional to the magnitude} above L cos and t (where A is the amplitude of the signal; co is the frequency; t is the delay value), it is necessary to observe the conditional / coacot / 1, i.e. when changing signal frequency in a wide range, it is necessary to consistently change the delay value.

The need for automatic or manual adjustment of the delay value leads to a decrease in the accuracy of measurements and an increase in the time measured1.

The purpose of the invention is to eliminate the need to adjust the delay time when measuring the amplitude of a harmonic signal in a wide frequency band.

For this, a structural-correlation voltmeter containing an autocorrelation channel made in the form of a serial connection of the delay line, a multiplying device and an integrator, as well as an indicator, while the second input of the multiplying device is connected to the input terminal of the voltmeter an additional autocorrelation channel connected parallel to the main channel and made in the form of a serial connection of additional delay lines, a multiplying device, and an integrator as well as two quadrants, an amplifier with a normalized gain factor, two adders, a square root extraction unit and an inverter, the input of the additional delay line is connected to the output of the main delay line, and the second input of the additional multiplying device with an input terminal of a voltmeter, the output of the main autocorrelation channel is connected via a quad and an amplifier with a normalized gain to the first inlet of the first adder, and the output of the additional autocorrelator This channel is connected through the second quad to the second input of the first adder and through an inverter to the second input of the second adder, the first input of which through the square root extraction block connects the output of the first adder and the output of the second adder connects to the indicator. The drawing shows the circuit of the proposed voltmeter. It contains shifters 1 and 2, integrators 3 and 4, delay lines 5 and 6, quadrants 7 and 8, amplifier 9 with normalized gain, adders 10 and 11, square root extractor 12, inverter 13 and indicator 14. The structural-correlation voltmeter works as follows. The input signal is fed to the first inputs of multipliers 1 and 2, directly to the second input of interlocking device 1 through delay 5, and to the second input of multiplier 2 through lines 5 and 6 of delay square. The outputs of multipliers 1 and 2 are connected to the inputs of integrators 3 and 4 of the OTBeTCTBeiHHO co. Part of a voltmeter from its input to the output of integrator 3 is the main autocorrel channel for measuring the amplitude, which is similar to the well-known. At its output, a signal (voltage) is formed, which is proportional to the value of the autocorrelation function of the measured signal at the delay value, determined by my parameters of the delay line 5. The part of the voltmeter from its input to the output of integrator 4 is the same as the main channel, but the time delay signal is doubled because the delay lines 5 and 6 are identical. The output signal of the main measurement channel is fed through the quad 7 and the thresholder 9 with the normalized coefficient is amplified at the first input of the adder 10, the second input of which through the second quadra 8 receives the output signal of the additional measurement channel. The output signal of the adder 10 is fed through the square root extraction unit to the first input of the adder 11, the second input of which through the inverter 13 receives the output signal of the secondary autocorrection channel. The output of the adder 11 is connected to the indicator 14. A part of the voltmeter from the outputs of the integrators 3 and 4 to the indicator 14 is a non-linear converter with two inputs and one output, the conversion characteristic of which is described by the formula where x is the output signal of the main measuring channel ion signal function); Xg is the output signal of the additional measurement channel (the value of the autocorrelation function of the stenal at double the delay time); y is the output signal of the adder 11 {the result of the nonlinear transformation of the values of the autocorrelation signal of the signal). For the relay autocorrelation function, the functions j and x, are equal to X kAco3a) t; X is kAcogScui where k is the channel gain factor of the meter. The result of the nonlinear transformation in this case is equal to Y k A and does not depend on the values of the frequency of the transmitter and the delay. Using this CTpyKTypHO.i "oprelational voltmeter to measure the amplitude of harmonic signals allows you to simplify the process of measuring, rocr. This measurement measure, since it is necessary to preliminarily adjust the delay value, reduce the measurement error due to the serious error caused by inaccurate adjustment of the delay value, especially at low signal-to-noise ratios.

Claims (1)

Invention Formula The structure is equipped with a Schunny voltmeter containing an autocorrection channel made as a serial connection of a delay line, a multiplying device: TBa and an integrator, as well as an indicator; the second input of the multiplying device together with the input of the delay line is connected to the input terminal of the voltmeter, characterized in that, in order to eliminate the time adjustment, the delay in measuring the amplitude of harmonic signals in a wide frequency band is provided with an additional autocorrelation channel connected in parallel but the fundamental channel and configured as a series connection of - ling additional minutes delay multiplier and integrator devices, also two Quad, amplifier normalized gain, two adders, a square root extraction unit and an inverter, the input of the additional delay line is connected to the output of the main delay line, and the second input of the additional multiplying device is connected to the input terminal of the voltmeter, the output of the main autocorrelation channel is connected via a quad and an amplifier with normalized gain to the first input of the first adder, and the output of the additional autocorrelation channel is connected via the second quad to to the second input of the first adder and through the inverter to the second input of the second adder, to the first input of which the output of the first adder is connected through the square root extraction unit, and the output of the second adder is connected to the indicator.