SU1404968A1 - Digital spectrum analyzer - Google Patents

Abstract

This invention relates to the field of radio metering technology. The digital spectrum analyzer (CAS) contains 1 clock pulse generator, 2 Walsh function generator, logic block 3 Equivalence, 4-7 reversible counters, frequency divider 8, triangular voltage generator 9, scaling amplifier 10, comparator 11, diode 12. TsAS has a higher accuracy of the analysis. 2 Il.

Description

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The invention relates to a radio measuring technique and can be used in radio engineering when carrying out spectral analysis of electrical signals.

The purpose of the invention is to improve the accuracy of the analysis.

FIG. 1 shows a block diagram of a digital spectrum analyzer; on. FIG. 2 - time diagrams of the process of its work.

The digital spectrum analyzer (Fig. 1) contains 1 clock pulse generator, 2 Walsh function generator, logic block 3 Equivalence, reversible counters 4-7 of a recording device, a series-connected frequency divider 8, a generator 9 of a triangular voltage and a series-connected scale amplifier 10 , a comparator 11 and a diode 12, the output of the generator 1 of clock pulses is connected to the input of a frequency divider 8, the counting inputs of reversible counters 4-7 and the input of the generator 2 Walsh functions, the outputs of which are connected the first inputs of logic block 3 Equivalence, its second input connected to the cathode of the diode 12, and outputs - to data inputs of the reversible counter of the recording device 4-7

The spectrum analyzer works in the case of calculating the first four Walsh coefficients as follows.

The clock pulses from the generator output 1 clock pulses arrive at the input of the frequency divider B, which generates pulses, synchronizing the 1st generator 9 of a triangular voltage. The output voltage of the generator 9 is fed to the non-inverting input of the comparator 11, to the inverting input of which the signal under test is fed through the scaling amplifier 10. At times when the voltage of the triangular generator 9 exceeds the voltage of the test signal, the voltage of the positive polarity is formed at the output of the comparator 11. When the triangular voltage is less than the voltage of the signal under study, the output voltage of the comparator 11 becomes negative. Assuming that, during the period of a triangular voltage, the signal under study varies slightly, we can assume that the width of the positive pulses is proportional to the instantaneous values of the signal under study. Thus, the analog signal under study is converted into a pulse width-modulated signal (PWM signal).

The PWM signal, consisting after passing through diode 12 of positive pulses with an amplitude of logical 1, arrives at the second inputs of the logical block 3 If the voltage of the PWM signal and the voltage of the Walsh function simultaneously take on the values of logical 1 or logical O, then in the reversible counters 4-7, the sum of the counting pulses from the gene Rathore 1 clock. If the levels of the PWM signal voltage and do not match. Walsh functions are subtracted pulses. From the outputs of the reversible counters 4-7 of the recording instrument, at the end of the decomposition period, the values of the spectral coefficients are removed.

The representation accuracy of the Walsh signal under study is determined by the number of calculated coefficients of the series. The maximum number of calculated coefficients and the accuracy of their calculation is limited by the minimum quantization period of the signal under study over time.

Claims (1)

Invention Formula A digital spectrum analyzer containing a series-connected clock pulse generator and a Walsh function generator, the output of which is connected to a register through the logic block. Equivalence is connected to a registering device: a device made in the form of reversible counters, as well as a scaling amplifier increase the accuracy of the analysis; additional connected frequency divider, triangular voltage generator, comparator and diode, the cathode of which is connected to the second inputs, are entered into it 31404968 logical block Equivalence, forks of the registering block, and the second comparator input - with the output of the scaling amplifier, whose input input frequency divider is connected to the output of the clock generator and the second inputs of the reversible counters are connected to the input of the device. iHIIIIHIIIIIIIIIIIIII (IIIHIi (| {lilil {|||||| lillllilH (MIHU eight I I I I (I I I I I (t five% Sh P p n n pppkpp. 2 L. П n 0 П ПППП l П ni t 0ue.Z