SU549751A1 - Low Frequency Spectrum Analyzer - Google Patents

Description

(LOW FREQUENCY SPECTRUM ANALYZER

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The invention relates to a radio measuring technique and can be used to create automatic analyzers of a low frequency spectrum of a sequential type.

Spectrum analyzers are known that contain Fourier component shapers, a multiplier, a clock generator, an adder, a division unit, and an indi-jator.

The disadvantage of these devices is the low speed and low accuracy of measurements.

Also known are low-frequency spectrum analyzers containing a series-connected input unit and a multiplier, the output of a sweep frequency generator is connected to another input, and a low-pass filter 2j.

A disadvantage of this device is the low accuracy of the analysis.

The purpose of the invention — an increase in the accuracy of the analysis — is achieved by the fact that a low-frequency spectrum analyzer containing a serially connected input unit and a multiplier, to another input of which is connected the output of a sweeping frequency generator,

to the low pass filter, equipped with an inverter and a combiner connected between the multiplier output and the low pass filter input; the input of the inverter is connected to the output of the input block, and its output is connected to another input of the adder.

The drawing shows a structural diagram of the analyzers. The analyzer contains an input unit 1, a multiplier 2, a low-pass filter 3, an oscillating frequency generator 4, an inverter 5 and an adder 6.

The analyzer works as follows.

From the input block 1 to the multiplier 2, the test voltage is given, having the form

to

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and.

..

yh

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Claims (2)

The other input of the multiplier 2 is supplied from the oscillator of the oscillating frequency 4. The multiplier can be made on the control resistance, which is our constant value R and the variable part of the DT controlled in accordance with the voltage margin of the generator 4. In In this case, the output of the intelligent resident is the voltage and and S-inn w t + -and X (g,). 1-cosS ") -eL) g where goes-DTZ / -I, a & -frequency generator 4 at the current time. This voltage, as well as the inverted input, goes to the inputs of the adder 6, the output of which contains zero beats near the frequency L-Qj and voltages whose frequency is equal to the sum that is easily filtered by the low-pass filter 3. Formula containing a series-connected input unit and a multiplier, to the other input of which the output of the oscillating frequency generator is connected, and a low-pass filter, characterized in that, in order to improve the accuracy of the analysis, it is equipped with an inverter combiner means connected between the output of the multiplier and the input of the low pass filter, the input of the inverter connected to the output of the input block and its output - to the other input of the adder. Sources of information taken into account during the examination: 1. USSR author's certificate No. 293215, G 01 R 23/16, 20.05.69. 2.Kriksunov V. G. Automatic analyzers of the spectra of electrical signals. Technique, Kiev, 1965, p. 96-101.