SU928246A1 - Multi-channel spectrum analyser - Google Patents

Description

(54) MULTI-DIAL ANALYSIS OF THE SPECTRA

The invention relates to a measurement technique and can be used to simultaneously measure the frequency spectrum of several signals or processes.

The known spectrum analyzer is a one-dimensional coherent ana-1 spectrum analyzer, a block of mirror galvanometers, a mask with a diaphragm, and a light-receiving sensor. When a well-known spectrum analyzer is operating in the output plane, the channel-to-channel spectral decomposition of the multichannel input function 1 takes place.

However, the well-known spectrum analyzer does not allow simultaneous quantitative measurement of the spectra in different channels simultaneously in spatial frequency. In addition, when reading the spectra of different channels 1 |, the errors in determining the relative frequency position of the spectral components as a result of fluctuations of the galvanometer mirrors are found. The closest technical solution to the invention is a multichannel spectrum analyzer, which contains a one-dimensional coherent spectrum analyzer, a block of mirror galvanometers, an oscillator, an optical slit, a cylindrical lens, light detectors, and a light beam oscilloscope. The mirror of the galvanometer unit, controlled by the external generator signal, is installed in the output focal plane of the cylindrical lens of a one-dimensional coherent spectrum analyzer, and the light rays reflected from each galvanometer, through an optical slit in the form of a narrow inclined line and a cylindrical lens, are fed to the corresponding light sources, connected to a light beam oscilloscope. In this setup, the spectra of the channel are produced by a corresponding individual light receiver due to the oscillatory motion of the corresponding mirror of the block of galvanometers 2.

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The disadvantage of the known multichannel spectrum analyzer is that it does not allow to produce synchronous at spatial frequencies, with beveled measurement accuracy

25 spectral picture of the multichannel process, i.e. two signals of the same frequency and power, recorded in two channels, can be removed as signals with different frequencies and amplitudes.

Claims (2)

30 These errors are particularly significant in the problems of the comparative analysis and identification of signals from their spectra. The purpose of the invention is to improve the accuracy of synchronous measurement of the spectra of various signals at elevated analysis rates. The goal is achieved — that a multi-channel light flux modulator, located between a coherent spectrum analyzer and a multi-channel light modulator, is inserted into a multichannel spectrum analyzer containing a one-dimensional coherent spectrum analyzer, a deflector made in the form of a controlled mirror galvanometer, a light receiver and a recorder deflector, wt. with a number of movable diaphragms, located in front of the light receiver and a bandpass filter unit installed between the light receiver and the recorder. The drawing shows a diagram of the analyzer.,. The iNorokalanny spectrum analyzer contains a one-dimensional coherent analyzer of the first spectrum, consisting of coherent light source 2, collimator 3, input transporant 4 with multichannel recording of the signals being studied and integrating cylindrical lens 5, modulator 6 of the net flow reference signals, deflector 7 in the form of a galvanometer, controlled by an external generator signal, a mask 8 with a number of movable diaphragms, located along the line, perpendicular to the spectral spectral images, light receiving device 9, a strip filter unit 10 and the registrar 1.1. The device works as follows. A coherent light source 2, such as a helium-neon laser, emits a narrow beam of light / which, by collimator 3, expands to six sizes and illuminates transporat 4 with a recording (density or phase) of the signals under study. When integrating a cylindrical lens 5, the rays of light fall on the mirror of the galvanometer deflector 7, installed so that reflecting from it, the spectrum of each channel is focused in the area of the corresponding diaphragm of the mask 8. Each aperture of the mask 8 selects one element of the spectrum in each channel. The luminous flux, passed through a mask with a number of diaphragms, is modulated by a modulator 6 of the luminous flux by a reference signal, each channel being modulated by its own frequency. Modulated light signals from all channels are collected by the light receiver 9, then separated by a bandpass filter unit 10 into signals of different channels and fed to the corresponding inputs of the recorder 11. A multi-channel spectrum analyzer allows the spectral pattern of a multi-channel signal to be read, while comparative measurements of the amplitudes and frequencies of the spectral components of different channels at elevated analysis rates. In addition, the use of a reference signal and band-pass filters in the analyzer of the modulator of the light flux allows the use of narrow-band amplifiers, which accordingly reduces the power of the noise at the output of the system. Claims A multichannel spectrum analyzer containing a one-dimensional coherent spectrum analyzer, a deflector made in the form of a controlled mirror galvanometer, a light receiver and a recorder, characterized in that, in order to improve the accuracy of synchronous measurement of the spectra of various signals at elevated analysis rates, the light stream modulator is supported by time signals, located between the coherent spectrum analyzer and the deflector, a mask with a number of moving diaphragms, located in front of the light receiver and a bandpass filter unit, installed between the light receiver and the recorder. Sources of information taken into account in the examination 1. Preston K. Coherent optical computing machines. M., Mir, 1974, p. 24-26, 289-2.90. 2. Authors certificate of the USSR 327416, cl. G 01 R 23/16, 1972.