SU834581A1 - Digital analyzer - Google Patents

Description

The invention relates to an electrical measurement technology and can be used to measure the spectrum, mutual spectrum and coherence coefficient. A digital analyzer containing a logarithmic analog-to-digital converter, two adders, a logarithmic code-to-linear converter, connected to a second adder, a random access memory, connected to a rewriting circuit of a second sum, a permanent storage device, a control unit, is known. - ny with all the blocks. However, the known digital analyzer does not allow to measure the mutual spectrum and coherence coefficient, as well as to present the measurement results in polar coordinates and on a logarithmic scale. The purpose of the invention is to expand the range of analysis. The goal is achieved by the fact that a digital analyzer containing an analog switch connected to the input of a logarithmic analog-digital converter, two adders, a converter of a logarithmic code into a linear, random access memory, a permanent memory, a converter of a linear code into a logarithmic memory and a control unit, additionally introduced shift register, memory register, linear code converter; an arctangent code and a digital switch, the inputs of which are connected to one of the outputs of the first adder, the output of a permanent storage device, the output of a logarithmic analog-to-digital converter, the output of a linear-to-code converter, and the second adder are connected between output converter logarith

a linear code and a random access memory output, the first adder is connected between the digital switch output and the shift register input, the output of which is connected to the memory register input and simultaneously to the serially connected linear-to-linear code converter, the linear tangent code of the arctangent and the operational memory the device, the second input of which is connected to the output of the linear code to log converter, is also connected to the second input register and the memory, the third input is connected to the output of the second adder and simultaneously to the input of the linear-to-log converter.

The drawing shows a block diagram of a digital analyzer,

The circuit includes series-connected analog switch 1 connected to the inputs of the analyzer LLvjH it, wo, logarithmic analogue i Az; /

LOGO-1 DIFFERENTIAL Converter (ADC; 2, digital switch 3, first adder 4, shift register 5, transducer 6 of logarithmic code B linear, second adder 7, DTHBiioe memory device 8, the output code of which is a measurement result, as well as a constant memory device 9, the output of which is connected to the input of digital switch 3, memory register 10, linear-to-log converter P, linear-code-to-arctangent converter 12, control unit 13, connected to all the blocks. The linear code transducer 11 is connected to the output of the second adder and is connected to the inputs of the random access memory .8, register 10 and digital switch 3. The register 10 also contains a second input, which is connected to the output of the shift register 5, and the output 10 of the register is connected to the input of the digital switch 3. The input of the converter 12 of the linear code into the code of the arctangeys is connected to the output of the converter 6 of the logarithmic code into the line code, and the output to the input of the random access memory 8,

The analyzer works as follows.

Claims (1)

When measuring the components of the Fourier transform, the first input signal is connected to the input of the converter 2, the logarithmic analog-to-digital conversion (ADC) of this signal using the converter 2, the transfer of the logarithmic ADC codes and the permanent memory 9 to the adder 4. From the output of the adder 4, the sum of the logarithms of the input voltage and sin-cos components, stored in the device 9, is fed through the shift register 5 (without the shift in this mode) to the transducer. 6 of the logarithmic code into the linear one, after h it is accumulated by the sin and cos components using the second adder 7 and the random access memory 8. In the random access memory 8, each cell under investigation has four cells for each frequency: two for storing and accumulating the sin and cos components , two for storing and accumulating the module and phase of the spectrum; in addition, in device 8, each frequency corresponds to 3 more cells: two for storing and accumulating the module and the phase of the mutual spectrum, and a third for storing the calculated value of the coefficient gerence After measuring and calculating one sample on the first channel, switch 1 connects the second channel (Ug--) to the input of converter 2, and a similar measurement and calculation is performed for the same sin-, cos- kitsi values extracted from device 9. After calculating the single value of the components of the permanent storage device 9 is retrieved for all channels on all channels, again analog switch 1 connects to the converter 2 the first channel (Upj (), and similar measurements and calculations are made. Measurement frequency ort gonal components are obtained by changing the sampling frequency of the storage cells 9 after the measurement of the sin, cos components for all frequencies and channels in the first section of the signal under investigation, they are converted into a polar coordinate system with the K module and phase 1 at the frequency of the i-j channel. The coordinate transformation equation has the following step: V 09 4 og ant i log2logS - "- anti logZlogGj, f rrarctg -4- arctg ant i log logS, 1" T li. J.- -logG j sin- component of the j-th input signal at the frequency; cos is the component of the jth input signal at frequency f -. implementing equation (1), the compiler S.-: is read from the operative memory of the device 8, transmitted through the second adder 7, converted into a logarithmic code in the converter 11, then transmitted through the digital switch 3 and the adder 4 to the register 5 where the doubling occurs code by shifting, after which the information is recorded through the converter 6 of the logarithmic code into the linear one and through the adder 7 is recorded into the third cell of the random access memory 8, corresponding to the frequency, to the j-th channel. A similar transformation is performed 1 | ad G:, after which the sum of two anti-logarithms in adder 7 is performed, then the obtained amount is transformed in converter 11, transmitted through commutator 3 and adder 4, the lower part of the register in the register is 5 hectares , which corresponds to multiplication by, further conversion to a linear code in the converter 6, and, finally, the calculated value of R, -; is written via adder 7 into random access memory 8. To implement equation (2), the component is read, transmitted through adder 7, converted into a logarithmic code in the transform. Hardly 11 and stored in register O, after which it is read from memory 8 by component and is converted to a logarithmic code in the I1 converter. Then, the obtained logarithm values are transferred through the switch 3 to the sum of the torus 4, where they are subtracted - then the information without the shift is cd 81. 6 is transmitted through shift register 5: converted into a linear code in converter 6, after which it is converted into an arc tangent code in converter 12 and written to the device 8 in the fourth cell, corresponding to the jth channel. To obtain a logarithmic representation (log and log Kf), the corresponding cells are read from device 8, transmitted through adder 7 to converter 11, after which the transformed information is again recorded in operational memory 8. Device definition and mutual phase spectrum of the 1st frequency channel j and (j + l) are produced in accordance with the equations: V / .V ° 9 (g - (i + oV)) To implement equation (E), it is READED from device 8, transmitted through adder 7, converted into converter 11 and stored in the register 10. Then it is read, transmitted through adder 7, converted into converter 1I "and then the resulting logarithmic codes through commutator 3 are fed to adder 4, where it is summed. The result of the sum without shift is transmitted through shift register 5, converted into a linear code in converter 6 and through The adder 7 is recorded in the device 8. The implementation of equation (4) is performed by subtracting in the adder 7 codes read from the device 8. To reduce the error due to the fluctuation of the measured spectral characteristics investigated random signal analyzer manufactured by averaging these parameters between the portions of the signal. Averaging is carried out by accumulating the characteristics measured at each site using the second summation 7 and the operational storage device 8. As a result, the averages are obtained. - / 4) The determination of the coherence coefficient between the j-th and (j +1) channels at the i-th frequency is made in accordance with the equation: i-j, + -1 i-n G - antitog-tog МН,. i jj-H -T- (og R, - (., f) To implement equation (5), it is read from device 8, through adder 7 is fed to converter 11, and then the converted code is stored in register 10. Next, it is read from device 8 and also through the adder 7 is fed to the converter 11. Logarithmic codes from the outputs of the converter P and register 10 through the switch 3 are fed to the adder 4, where their sum is determined, which is fed to the input of the shift register 5 The latter shifts the amount by one bit to the lower bits, which provides multiplication by 4 I send information from the output of the shift register 5 to the register 10, then read G 7 from device 8 and via adder 7 feeds to converter 11, after which the logarithmic codes from the outputs of converter 11 and register 10 flow through switch 3 to the sum of matrix 4, where the subtraction is performed. The result obtained without the shift is transmitted through the shift register 5, is converted into a linear code in the transmitter B and through the adder 7 is written in the device 8. Also, a digital analyzer using logarithmic transformations allows you to measure the mutual spectrum and coherence coefficient, as well as present the measurement results in polar coordinates and logarithmic scale. This makes it possible to apply it to automate the scientific experiment, which ensures an increase in labor productivity in measuring the statistical characteristics of random signals. The use of the analyzer in the radio and radio electronic industries will improve the efficiency of obtaining the characteristics of random signals and the accuracy of measurement information 834581.8 by examining a larger number of informative characteristics of random signals, the Invention Formula A digital analyzer containing an analog switch connected to the input of a logarithmic analog-digital converter, two adder, converter logarithmic code into linear, -operative memory Real estate, read-only memory, linear-to-log converter and control unit, characterized in that, in order to expand the analysis range, a shift register, a memory register, a linear code converter in an arctangent code and a digital switch, whose inputs associated with one of the outputs of the first adder, the output of a persistent storage device, the output of a logarithmic analog-digital converter, with the output of a linear code converter into a logarithmic and with the output of the memory register, the second adder being connected between the output of the logarithmic code to the linear converter and the output of the operational memory, the first adder is connected between the output of the digital switch and the input of the shift register, the output of which is connected to the input of the memory register and simultaneously connected to the converter, logarithmic code to linear,. linear code to arctangent transducer and operational memory. The second device is connected to the second memory register input, the third input is connected to the output of the second adder and at the same time to the input of the linear code to log converter. Sources of information taken into account in the examination 1. AjBTOpcKoe USSR certificate № 473118, cl. G 01 R 237.16, 1975.