SU643809A1 - Optronic spectrum analyzer - Google Patents

Description

-one - .

The invention relates to the field of statistical measurements of random processes and can be widely used in many areas of national economy.

The optoelectronic spectrum analyzer is designed to analyze the frequency properties of a random process and characterizes the intensity of various frequency components or the average power per unit frequency band.

An optical-electronic spectral analyzer i is known, the disadvantage of which is a low frequency resolution.

The prototype of the device should be optoelectronic correlator 21 containing a constant voltage source, a sectioned delay line AND whose input is the analyzer input, and the outputs are connected to the corresponding electrical signal-to-light converters, outputs

 which are optically connected with the corresponding fibers of the first group, the second group of fibers optically connected through a collimator to an amplitude light modulator, an array of photodetectors whose outputs are connected to the corresponding inputs of the integrator unit, a mirror placed on the path of a separate optical beam in front. an optical array of optical sensors connected to the input of an additional receiver, the output of which is connected to the first input of the receiver, the output of which is connected to the electrical input of the amplitude modulator. The aim of the invention is to increase the speed of an optical-electronic spectrum analyzer.

The goal is achieved by introducing an inverse collimator placed between the amplitude light modulator and a photodetector array, an additional electrical signal-to-luminous flux converter, connected to the output of a constant voltage source installed in front of the MiatopoM, and a matrix transparency, the optomatrix of which is placed on the optical optomatrix, which has an optical driver. the first group and the cell columns - narbtiv optical inputs of the optical fibers of the second group, while the second input of the amplifier is connected to the input ode analyzer.

The invention is illustrated by the drawing in which the following designations are accepted: input terminal 1, partitioned delay line 2, converting an electrical signal into a light flux 3, first group of light guides 4, matrix transparency 5, first three collimator, additional electrical signal converter into the light flux 8, terminal of a constant voltage source 9, amplitude light modulator 16, reverse il collimator, whose: and photodetector array 12, integrating unit 13, output terminals 14, mirror 15, feedback photo detector 16, error amplifier 17 “: Input terminal 1 is connected to series-connected elements of a partitioned delay line 2, the output of each of which is also connected to the corresponding pre-rat 3 electrical signal into the light flux. The 3 light streams emitted by the transducers through the first group of optical fibers 4 are transferred line by line to the maT |) Icicle 5, At the exit of the transparency 5 relative to its columns, the second group of lights 1 T {m

x (t) x (t-mu-t cos 235., o

 AI S X (tl

SCnubtsj i Imr-t -. constant coefficient where A is stationary random X (-t) i, f processes; tn AL — Specified number of time intervals during the process study time; And m N is the specified number of discrete values of the spectral components of the process; At; - the relative value of the delay time; D «U is the sampling frequency range of the frequency range Si of the input stationary random processes X (t).

Diodes 6, Light FLOWS that have passed the second group of optical fibers 6, pass through the first collimator 7, to which the luminous flux from the additional converter of the electric signal to the luminous flux 8 connected to the source terminal 9 of the alternating voltage falls, to the input of the amplitude module the torus of light 10, the output light of which passes to the reverse collimator 11, which serves to split a single beam of light into a countable set of light beams in the space of the geometry of the light in which the beams of light are incident on g of the first collimator 1, the Countable set of split beams of light from the output of the reverse collimator 11 (except

the light flux emitted by the transducer, the user 8) falls on the corresponding cell of the array of photodetectors 12. each electrical output of which is connected, by a corresponding input of the integrating unit 13, the outputs of which are connected to the output terminals 14. The luminous flux emitted by the converter 8 is fed through a mirror 15 to the input of a feedback photosensor 16, the electrical output of which is connected to the first input of the error amplifier 17, the second input of which is connected to the input terminal 1, and the output is connected to the electrical input of the amplitude light modulator 10.

The device works as follows .... .

The spectral density of a stationary random process is determined by the formula: ..

iS.1

dt, N j A stationary random process (h) is applied to terminal 1. At the outputs of the elements of the delay line, the number of which is equal. 14, delayed relative to time by the magnitude A, T, the spectral voltages will arise, which are subsequently converted by converters 3 into the corresponding light fluxes, directed by means of light guides 4 to the transparency 5. The transparency S is a two-dimensional m, and 1 film has: In 1-M and AND 1-m f4 partitions of i along the axes, each cell of the photo v

film has a certain light transmission coefficient corresponding to the numerical value determined by

expression (1).

. The distribution of the light guides 4 in the PCOCTufm, P J of the transparency 5 is carried out in such a way that the light guide 4, on which the information from the primary converter 3 is irradiated, irradiates the entire first row of the transparency 5. Similarly, the remaining lines of the transparency 5 are located.

Passed line by line banner 5 information light streams

fmnVn -:

Where

 coefficients of light transmission of transparency cells 5, arrive at the second group of optical fibers b, of which one is strictly set relative to columns AND transparency 5.

The light fluxes that passed the second group of light waves 6 together with the light flux HO (t) emitted by the optic flux. light point 8, fall on the scale 7 torus 7, which compresses the space; but distributed light fluxes into a single stream passing through a sequentially installed amplitude modulator of a light 10% collimator 11 along the optical axis. Collimator 11 serves-for splitting a single beam of light with the same spatial-geometrical configuration of beams St. the one in which they were located in the plane of the entrance of the collimator 7. Spatially distributed light fluxes from the entrance of the light colaimator 11, incident on. Corresponding photodetector cells. Matrix 12 is converted to ed Strych signals.

) 5 (and., „P) tt-WAT SC)

gd is a conversion factor; S (Uynp) - control signal acting on the amplitude modulator of the light

 iO - ..; . Luminous flux Nd (-b), reflected

from the mirror 15, after being converted by the photoreceiver 16 to the aptical signal S / olt), is applied to the first input of the error amplifier 17. The second input of the error amplifier 17 is divoi with the input terminal to which the input stationary random is fed; process.

Under the influence of these two signals, the error amplifier 17 generates a control signal

S (U ,, p) - V (i) / Vo (t), (4)

KOTOpbift, acting on the amplitude modulator of the light 10, changes the intensity of the radiation of the light fluxes passing through it. This process continues until C (1 s; O

 and.

The photo-receiving matrix 12 is connected to the integration unit 13, the outputs of which, taking into account the practical invariance of the control voltage

and V (t) as well

and

iinp

To the various types of transformations described above, we finally get:

Spawn))

20

I,

(t-mA-c) cos

 Jv (t) v

N

mn

where i is the block and tagging time constant. The described spectrum analyzer provides high speed by being compact and reliable.

Claims (2)

1. US patent number 3355579, MKI 235-181, 1976. 2. USSR author's certificate No. 557669, cl. G06 G 9/00, 1976.