SU943596A1 - Spectrum analyzer - Google Patents

Description

(5) SPECTRUM ANALYZER

one

This invention relates to a radio metering technique and is intended to measure amplitude spectra and phases of electrical signals.

Closest to the present invention is an analyzer comprising a bottom filter, a switch, a voltage-to-voltage converter, reversible counters, and til indicators.

The disadvantage of it is the limited scope due to the impossibility of measuring the amplitude and phase of the spectral components of the si-nal.

The purpose of the invention is to expand the functionality of the analyzer.

The goal is achieved by the fact that a spectrum analyzer containing a low-pass filter, attenuator, electronic switch, voltage to voltage converter

pulses, two reversible quadrature channel counters, a control unit and indicators, the low-pass filter is connected to the electronic switch directly and through an attenuator, the output of the electronic switch is connected to the converter input, the counting inputs of the reversible counters are connected to each other and to the converter output,

10a, the control unit is connected to an electronic switch, a voltage to pulse number converter, reversible counters, a discrete auxiliary quadrature voltage generator, two controllable discrete attenuators, an amplitude channel counter, a comparison unit, a three register, a decoder, and a reversible counter are added channel phase

20 wherein the outputs of the reversing quadrature channel counters are connected to the signal inputs of the respective quadrature component registers. the outputs of the numerical bits of which are connected to the inputs of two indicators of quadrature components and to the control inputs of the corresponding controlled discrete attenuators, the outputs of the discrete generator of auxiliary quadrature voltages are connected to the signal inputs of controlled discrete attenuators, the outputs of which are connected to the additional inputs of the electronic the switch, the output of the voltage converter into the number of pulses is additionally connected to the counting input of the amplitude channel counter, the output of which connected to the first input of the comparison unit and to the signal input of the amplitude register, the output of the comparison unit is connected to the clock input of the amplitude register and to the input of the control unit, the output of the amplitude register is connected to the second input of the comparison unit and to the amplitude indicator, outputs of the sign bits of the quadrature composition registers connected to the input / decoder, the output connected to the control input of the reversible counter of the phase channel, the output of which is connected to the input of the phase indicator, the outputs of the control unit are associated with corresponding inputs of a discrete generator of auxiliary quadrature voltages, a decoder, a reversible channel counter, a counter, registers, and a comparison unit. The drawing shows the structures on the spectrum analyzer circuit, the circuit contains a low-pass filter 1, an attenuator 2, an electronic switch 3, a voltage to pulse converter, reversible counters 5 and 6 of the quadrature channels, registers 7 and 8 of the quadrature components, indicators 9 and 10 quadrature components, controlled discrete attenuators 11. and 12, discrete generator 13 auxiliary quadrature voltages amplitude channel counter 1, comparison unit 15, amplitude register 16, control unit 17, amplitude indicator 18, de ifrator 19, reversible counter 20 and channel phase indica 21 Torr phase. The analyzer works as follows

at once.

Claims (1)

Attenuator 2 provides attenuation of the signal at fixed levels of the corresponding registers 7 and 8 of the quadrature components. The control block 17 on each clock cycle x, the number of which is determined by the rc; the number of levels of quantization of the reference oscillations. Switch 3 alternately and at an increased sampling rate delivers the full and attenuated attenuator 2 voltage of the input signal to the input of the voltage converter 4 to the number of pulses. Pulses from the output of converter C are summed and subtracted at appropriate intervals in reversible counters 5 and 6 of the quadrature channels, while the contents of reversing counters 5 and 6 correspond to the values of m of the sine and cosine components of the harmonic spectrum for the analyzed frequency. In order to reduce the effect of uncompensated odd harmonics in the spectrum of piecewise-constant reference oscillations, these harmonics are suppressed in the input signal spectrum by low-pass filter 1, control unit 17 drives a converter, reversible counters 5 and 6, switch 3 and after repeating the measurement cycle the quadrature components of the spectrum a specified number of times (1, 2, 3, etc., i.e. the completion of the cycle of the averaging quadrature components, puts the analyzer into the mode of calculating the amplitude and phase of the spectral component by its measured quadratures, for which it overwrites the contents of the reversible counters 5 and 6 into the registers 7 and 8 of the quadrature components. Based on the analysis of the sign bits of the registers 7 and 8 by the decoder 19, the control unit 17 sets the operation mode (addition or subtraction) of the reversible counter 20 and writes into it the number corresponding to the initial value of the phase O, 180 or 360 degrees, zeroes the register 16 and turns on the discrete generator 13 auxiliary quadrature voltages. The multiplication of the moduli (amplitudes) of the measured quadrature components of the spectrum by the corresponding auxiliary voltages of the generator 13 is carried out in controlled discrete attenuators 11 and 12, and the attenuation coefficients p 2 are set by the contents of the phase increment of the auxiliary sinus and cosine reference voltages that the counter is nullified. in parallel with the signal conversion and alternately connects the outputs of the controlled discrete attenuators 11 and 12 to the input of the sample gate 4 via electronic switch 3 and connects the counting input of the counter H to the output of the converter k. Block 15 compares the contents of counter H and register 16. If the number recorded in counter 1 is greater than or equal to the number recorded in register 16, then the output of comparison block 15 skips the clock pulse of control block 17 to allow the counter contents to be overwritten U to 16. If the number recorded in the AND counter is less than the number recorded in register 16, the calculation of the amplitude and phase of the spectral component from its quadrature components stops until the results of the next cycle of measurement (averaging) are obtained GOVERNMENTAL components and the information on the indicators 18 and 21 corresponds to the amplitude and phase of the spectral component. Thus, the analyzer provides the possibility of cyclically measuring the amplitude and phase of the spectrum along with its quadrature components in real time, which expands its scope. A spectrum analyzer comprising a low-pass filter, an attenuator, an electronic switch, a voltage-to-pulse converter, two reversible quad-channel counters, a control unit, and indicators, the low-pass filter connected to the electronic switch directly and through an attenuator, the electronic output the switch is connected to the input of the converter, the counting inputs of the reversible meters are connected to each other and to the output of the converter, and the control unit is connected to the electronic switch, voltage converter in the number of pulses, reversible and counters, characterized in that, in order to extend the functionality, it additionally introduced a discrete auxiliary quadrature voltage generator, two controlled discrete attenuators, an amplitude channel counter, a comparison unit, three registers , the decoder and the reversible counter of the phase channel, and the outputs of the reversing quadrature channel counters are connected to the signal inputs of the corresponding registers of quadrature composition The outputs of the numerical bits of which are connected to the inputs of two quadrature component indicators and to the control inputs of the corresponding f-wx discrete attenuators, the outputs of the auxiliary quadrature voltage generator are connected to the signal inputs of the controlled discrete attenuators whose outputs are connected to additional inputs of the electronic switch, the output of the voltage converter in the number of pulses is additionally connected to the counting input of the amplitude channel counter, the output to It is connected to the first input of the comparison unit and to the signal input of the amplitude register, the output of the comparison unit is connected to the clock input of the amplitude register and to the input of the control unit, the output of the amplitude register is connected to the second input of the comparison unit and to the amplitude indicator, the outputs of the quadrature quadrature component registers Connected to the inputs of the decoder, the output connected to the control input reversing. the phase channel counter, the output of which is connected to the phase indicator input, the outputs of the control unit are connected to the corresponding inputs of the discrete auxiliary quadrature voltage generator, the decoder, the reversible phase channel counter, the counter, registers and the comparison unit. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 610026, cl. (i 01R 23/16, 1978. / . .i. .