SU834589A1 - Signal shaper with predetermined non-linear distortion coefficient values - Google Patents

Description

(54) FORMER OF SIGNAL WITH GIVEN VALUES OF NONLINEAR DISTORTION COEFFICIENT

one

The invention relates to the field of radio engineering measurements, in particular, to devices for generating signals calibrated with a non-linear distortion factor (SOI). The invention can be used to calibrate and test nonlinear distortion meters and other devices.

A device for generating a signal calibrated by a SOI is known, in which sinusoidal signals from two oscillators with frequencies O. and 2 SI are not summed by a voltage divider, their levels are komdariir using a voltmeter and an exemplary divider, while establishing a certain ratio between their levels j.

The disadvantage of this method is the existence of a measurement (comparing) process when specifying each SOI value, which complicates the device and increases the time required to establish the desired SOI value and, in general, the verification time. In addition, the generated signal

has a limited number of harmonics.

The closest in technical essence to the present invention is a device implementing a method of generating a signal calibrated by a PICN, comprising a linear amplifier, a limiter, a limited signal repeater, as well as a source of reference voltage, a spectrum analyzer and an oscillographic indicator

The operation of the device is based on the limitation of a sinusoidal signal, the limitation level of which is determined by the zero value of the signal of one of the harmonics at the limiter output, and the nonlinear distortion factor of the received signal is determined by the decomposition coefficient in the Fourier series of the limited sinusoidal signal for cut-off angles at which the harmonic component The vanishing function vanishes. At the same time, some initial angle θ383 of the limiter chop is introduced and the anapizer spectrum is adjusted to a certain harmonic component of the output signal, and then the cut-off angle is adjusted to zero, while the sensitivity of the spectrum analyzer 2 increases. when specifying each value of a SOI, which significantly complicates the device, increases the scan time and cost of the device. The purpose of the invention is to improve the accuracy of signal formation. The goal is achieved by the fact that an input repeater and a series-connected differential voltage divider and an output follower are inputted to a signal conditioner with a given nonlinear distortion coefficient, containing a series connected limiter and a repeater, the first input of the differential voltage divider connected to the output The secondary repeater and the input limit the l, and the second input - with the output of the repeater. The limiter is made with a constant precision cut-off angle. The drawing shows the function of the device. The device contains an input repeater 1, a differential divider 2, a limiter 3 with a constant cut-off angle, a repeater 4, an output repeater 5. The device operates as follows. A sinusoidal signal with a unit amplitude through the input repeater 1 is fed to the input of the differential voltage divider 2. The same signal is limited by a limiter 3, having a constant cut-off angle of 90, and a transmission coefficient equal to one. At the output of the limiter, the signal has the form of cone pulses, which through repeater 4 are fed to the second input of the differential divider 2. Due to the constant cut-off angle of limiter 3, the signal at its output has a constant SOI value equal to 2 / gV (.4r) .. 00% 4i52 (i) Thus, a sinusoidal signal and a signal limited to a constant cut-off angle are differentially combined. Depending on the position of the output of the differential divider 2, taking into account its parts and. To (1-p), where R is the total resistance of the divider, through the output repeater 5 to the output of the device. The signal is received by the signal UBb, / 5 "t-t-Us" - | r 751iаС - М .... jj From where. ((5iVl4SLt SOI of the generated signal is set by the division factor n of the differential divider 2; Since the SOI of the output signal U (-4г1% (4)% ... -ioo%, l-fn, then taking into account the expression (1) we finally get It is clear from this expression that the SOI of the signal being generated is functionally connected to the division factor n of the differential divider 2 through the SOI KI {signal generated by the limiter 3. From here comes the need for normal functioning post the limiting 3 cut-off angle and the stable, so that the calibrated K values of the output signal generated by the proposed method depend entirely on the division factor n of the differential divider 2. For the limiter implemented in the device implementing the proposed method, the cut-off angle is constant and equal to 90 for him, as shown above, Kg is equal to 43.522%. Thus, the assignment of SOI values is reduced to switching the output of the differential divider 2, the values of the division factor of which are not preliminarily calculated The values of the SOI.

Claims (2)

Invention Formula . A signal conditioner with predetermined values of the nonlinear distortion coefficient containing a series-connected limiter and a repeater, characterized in that, in order to improve the accuracy of forming the signal, the input repeater and the series-connected differential voltage divider and output follower are entered into it, the first input; the differential divider is connected to the output of the input repeater and the input of the limiter, and the second input is connected to the output of the repeater M9 2. Shaper according to claim 1, characterized in that the limiting body is made with a constant precision cut-off angle. Sources of information taken into account in the examination 1. Instructions 200-64. Check for the sake of: measuring instruments standard. 1965, p. 315-329, Fig.4. 2. Petrov NB New device for testing scientific research institutes. Works of metrological institutes. Research in the field of radio measurements. Issue 9, Kharkov, 1972, p. 47-54. schhod