SU600461A1 - Wide-band autocorrelation voltmeter - Google Patents

Description

one

The invention relates to measurement technology and can be used to estimate the amplitude of a harmonic signal against the background of noise in a wide frequency band.

Single-channel meters with analog or relay multiplication are known, the meters of autocorrelation functions and the amplitude meters based on the same principle of the amplitude and my characteristics of the harmonic signal in the 4) operation noise.

The disadvantage of such measurements is that it is necessary to adjust the magnitude of the delay of Kit by the frequency of the signal. By their very nature, they are search engines that provide the maximum value of the constant component of the OUTPUT process. Due to the presence in the closed price of regulating the inertial element (integrator), search engine (detection) sigial is a long transition process, resulting in an increase in the evaluation time and complication of its accuracy.

A mutually correlated cyopic voltmeter is also known, which contains a tunable reference oscillator, an adder, an indicator and two quadrature channels consisting of a multiplier, an integrator and a square 2. The estimated signal is processed in two (Quadrature -channels, in a result} this microvoltmeter is insensitive to the initial phase of the signal. The disadvantage of a mutual-relay voltmeter is that you need to search for (detect) the signal being evaluated. The more frequently analyzed ny above range u selective properties voltmeter, the more the seek time over the entire frequency dianazone.

Hell is a real p1, his discovery is

sokrats; epne time time, the amplitude of the signal of unknown frequency. The goal is achieved by the fact that a voltmeter contains a multiplier multiplier, one of the inputs of which is connected to the input of the voltmeter, and the second is

to the output of the reference frequency generator, and an indicator, according to the invention, are introduced in series connected to a differential frequency selection unit, delay line, additional multiplier, band-pass filter

detector, included between the output of the multiplier and the indicator input, / and the second input of the additional multiplier is connected to the input of the voltmeter.

The drawing presents a block diagram of the proposed voltmeter.

The voltmeter contains a multiplier 1, a reference oscillator 2 of a constant frequency, blocks 3 are allocated a difference e smmarn () th frequency, a delay line 4, block 5 is an additional

multiply (multiplier), band-pass filter. 4 "", V / V. "-X". ; -..., //; L. ..- jr 3 ../,. U ,, .. .. . , () CO average frequency, the frequency of the reference detector 2, the envelope detector 8 and the 1ndt cathore 8. The input signal is fed to the inputs multiplied. Read. I n 5. Input multiplier 1 nod1KL1Ochen generator} 2, and the output unit 3 n delay line 4 - to the second input of the unit 5. The output of the unit 5 is connected via a loop fn, 1 r 6 n detector 7 with the indicator 8. The voltmeter works as follows. In multiplier 1, the input and reference signals are multiplied. In Olorp 2, a separation is shifted to the spectral co-component shifted by the frequency of the reference signal. After the line of delay 4, the incoming signal has the form: SI - L cos (yes - w „) t - ((- and)„. In block 5, the input signal and output signal of delay signal 4 are multiplied. The result is multiplied and of the two terms: s1) -. C08 S / 55 --- LCO (i- „) / - (“ -) + - - cos - CUT - o ({w „(+.). (2) + - COS 2vo / ш (- г) The first term is equal to, the second is removed from (OO. Band-pass filter 6 (for example, quartz filter) with a medium frequency yuo passes the term with a frequency of 0) 0 n with an amplitude of bending around A other than the frequency 0) 0 , components in letters of middle yute. Since the BAND filter 6 is the integrator for the multiplication results represented in the formula (2, the frequencies differ from co), and the factors contain terms that are time-shifted relative to each other, the proposed wideband autocorrelation voltmeter works similarly to the correlator. The components of the schum, which enter the input together with the signal, decrease as the i increase in the time interval according to the autocorel function of the integral function. The detector 7 serves to highlight the envelope (square This input signal.) Ka: K detector is phase-sensitive, the phase of the first term tor in formula (2) will not affect; pa the measurement result of the regular component of this term. Consequently, no additional time is required to get the signal, because The measurement result is invariant with respect to the frequency of the Signal. The proposed voltmeter makes it possible to shorten the measurement time. In addition, it is simpler because it does not contain a signal search system. The voltmeter provides the ability to match the signal frequency with the operating frequency of the delay line, which in turn allows the use of standard delay lines. Formula II 3 o bree and a wide bandwidth auto-correlation voltmeter containing a multiplier, one of the inputs of which is connected to the input of the voltmeter, and the second iK to the output of the reference frequency generator, and those that, in order to improve speed Measurements of the amplitude of a signal of unknown frequency, a serially connected difference frequency allocation unit, a delay line, an additional multiplier, a voice filter and a detector, connected between the output of the multiplier and the indicator input, are inputted in series swarm additional input of the multiplier is connected to the input of the voltmeter. Sources of information taken in the course of the examination 1.Zhovinsky V.P. et al. Correlation devices. M., “Energii, 1974. 2. Mizyuk L. Ya. N. et al. Correlation micrometer voltmeter. Advanced scientific and technical experience, No. 18-66-1355/108, 1966.