SU995285A1 - Multichannel panoramic receiver - Google Patents

Description

The invention relates to radio engineering and can be used to assess and control the range of radiation by radioelectronic. means of determining the type of received signals and their time-frequency analysis.

A panoramic receiver is known, with a keep & mixer, (compression filter indicator, amplitude detector and local oscillator, whose frequency varies according to the sawtooth law 1.

The band of the panoramic view portions of the known receiver is determined by the bandwidth of the Pe of the compression filter and the frequency deviation of the local oscillator. For guaranteed detection of each radio pulse, the conditions for matching the linear frequency-modulated oscillations with the pulse characteristic of the compression filter must be met.

.

l {

AChL.

sh,

W lat | c t

I et IftHNV.

where4 | 64g is the rate of change of the oscillation frequency.

Due to the difficulty of simultaneously fulfilling conditions (1) and (2), the device does not have a wide enough panoramic viewing band.

The closest in technical essence to the proposed technical entity is a multichannel panoramic receiver containing N frequency channels combined at the inputs, a synchronizer, an indicator connected in series with an L-input mixer and the first video amplifier whose course is connected to the indicator's power input, each frequency 1 the channel contains an input bandpass amplifier, an amplitude detector — and an output-: output key., the output of which is connected to the corresponding input of the L-input cyiva aTOpa, and the control inputs

20 dinen with the corresponding output of the synchronizer. In the device, the frequency band of the input signal is divided by N-input band-pass amplifiers with C 21.

25

However, the accuracy of the analysis in the device is not high enough due to the relatively wide bandwidth of each input bandpass amplifiers.

The purpose of the invention “rot is the precision of the analysis of loading frequency range,

The goal is achieved by the fact that a multichannel panoramic receiver containing N frequency inputs connected to the inputs, a synchronizer, an indicator, an N-input accumulator connected in series, and a first video amplifier whose output is connected to an indicator speaker, each frequency channel of which contains an input band amplifier, an amplitude detector and an output switch, the output of which is connected to the corresponding input of the N-input adder, and the control input is connected to the corresponding output synchronizer a, a sawtooth voltage generator, the triggering input of which is connected to the first clock output of the synchronizer, is inserted between the second clock output of the synchronizer and the capacitance input of the indicator. An sequential adjustable delay element, a gating pulse generator and a second video amplifier are connected in series between the output of the N-inputQ the adder and the frame scan input of the indicator, the line scan input of which is connected to the second clock output of the synchronizer, is switched on a selector, the control input of which is connected to a gating pulse generator, a controlled oscillator is inserted into each frequency channel, the control input of which is connected to the saw-voltage generator output, the melody of the input of the input bandpass amplifier and the amplitude detector input are connected in series to the mixer, the other input is connected to the output of the controlled oscillator , and. a compression filter, and between the output of the amplitude detector and the input of the output key are connected in series a S-tap delay element and an additional N-input adder.

The drawing shows a structural electrical circuit of the device. The multichannel panoramic receiver contains frequency channels 1, synchronizer 2, indicator 3, N-input adder 4, first video amplifier 5, input bandwidth amplifiers 6, amplitude detectors 7, output switches 8, sawtooth voltage generator 9, adjustable delay element 10, generator o 11 gating pulses of a SECOND amplifier 12, a selector 13, controlled generators 14, mixers 15, compression filters 16, N-tap delay elements 17 and additional N-input adders 18.

The device. {Works as follows 6 times.

The radio signals with the modulation parameters of the envelope and phase modulation are fed to the input of the input bandwidth amplifiers of 6 N frequency channels 1. Frequency channels 1 are identical in their operating principle, have equal frequency bands of guaranteed panoramic view, and the same intermediate frequency fp.C using input polar amplifiers 6, the studied frequency range Afo is divided into a number of adjacent bands D. The width of the bandwidth of each input band amplifier 6 is equal to the guaranteed panoramic band. PO1 Filtered and amplified radio input signals from the outputs of the input bandpass amplifiers 6. Go to the inputs of the mixers 15. Continuous frequency-modulated (LFM) oscillations from the outputs of the controlled oscillators are fed to the other inputs of the mixers 15 14. Linear frequency modulation of the oscillators of the controlled oscillators 14 is carried out by the saw-tooth voltage supplied to their control inputs from the output of the saw-tooth generator 9. The generator 9 is started by short pulses of synchronizer 2. Period the following short start pulses 1 o. is determined by the period of adjustment of the chirp oscillations of the controlled oscillator 14, T t, e, T ..,, according to conditions (1) and (2) for g of the detected detection of each radio pulse of any duration the adjustment period is

Тг 1 / 21Гсф,

where Tsf is the duration of the impulse response of the compression filter 16,

To guarantee detection of radio signals with a duration of 7 :; 77С (, ф the period of tuning the chirp oscillations can be chosen from the condition

 St1m g 5 Sf

Claims (2)

In controlled oscillators 14, the input radio signals are converted into chirp nepBOti radio pulses of the intermediate frequency fnm and fed to filters 16. The transformation of the input frequencies of radio signals in all frequency channels 1 with pulse compression to the same intermediate frequency is provided by selecting average values of the tuned frequency of the controlled generators 14 In filters 16, the pulse characteristics are convolved with the received chirp radio pulses. In this case, coherent accumulation is made, their components. As a result, at the output, time-compressed (shortened in duration) in K Psfcf are formed. Once and increased in amplitude in the MC times the pulses. The envelopes of these pulses are extracted using amplitude detectors 7, the temporal position of the shortened pulses at the output of the filters 16, ay, therefore, the video pulses at the output of the amplitude detectors 7, relative to the beginning of the tuning of the controlled oscillators 14, is determined by the carrier frequencies of the input signals on the time-frequency plane, it is determined by the carrier frequencies of the input signals and the time of their arrival. This location contains information about the modulating functions of the input radio signals and their frequency-time parameters. This offered device allows overlapping a given range of frequencies to be studied, using identical filters 16 in frequency channels 1 with guaranteed panoramic view band By-, lo - MP - - (3) For an undistorted and lossless display of the relative position of shortened video pulses on the screen of a wideband single beam indicator in frequency-time coordinates, these video pulses are fed from the amp outputs of the detector detectors 7 to the inputs of the N-OT delay delay elements 17. The N-OT drive elements 17 are for time delay (storage, accumulation) of shortened video pulses. The taps in the N-tap delay elements 17 are evenly spaced (equidistant). The delay time between adjacent taps is equal to the restructuring period of the controlled oscillators 14. The total delay time in one ta-tap delay element 17 is NT. Such a common delay and its uniform discrete distribution between the taps are necessary to eliminate the loss of the time-frequency information at the outputs of the frequency channels 1 with their subsequent sequential polling. I Each shortened video pulse appears successively through all N times of the corresponding N-tap delay element 17. Since each tap of the K-tap latency 17 is connected via an additional N-BXO-D-adder 18 to the information input of the output key 8, then over time NT to each. a shortened video impulse will affect this input through time C - - 3 Tr. The control inputs of the corresponding output switches 8 are given a interrogation pulse of duration TGV. during the duration of the interrogation pulse at the output of the output key 8, all video pulses received at the output of the amplitude detector 7 of frequency channel 1 during the time NT will pass. In other words, all signals received and processed in any of the frequency channels 1 during the time NT, ..., are transmitted to the outputs of the corresponding key switches 8 during the time T (. At the same time, the temporal position of the shortened video pulses within the duration Tp is determined by the carriers ( input signals, if a continuous signal is received, or during a time NT, radio pulses are received without intrapulse frequency modulation with a duration of WIJ, /, then the device performs a non-coherent accumulation of WssN pulses. For these signals, the probability of correct detection is increased. From the outputs of the output switches B, the shortened video pulses are fed to the corresponding inputs of the N-input adder 4, which combines the output channel frequency-time information during NT, .. At the output of the N-input adder 4, the time interval NT, equal to the length of the guaranteed panoramic view of the U-band, will be divided into N sections. The temporary position of the shortened channel video pulses within each section does not determine total frequencies of input signals. From the output of the N-in. Ard adder 4, the shortened video pulses are fed through the first video amplifier 5 to the speaker input indicator 3. On the screen of the indicator 3 line and frame scan are formed. The duration of the horizontal (vertical, frequency) sweep is consistent with the polling time of all frequency channels 1, i.e. T (.Nt; Q. In this case, frequency information will be displayed on every N-th part of the line scan during NT time, - from the output of the corresponding frequency channel 1. The duration of the frame (horizontal, time) scan is set to a scale convenient for observation. As a result, a highly informative time-frequency signal panorama of the investigated range, equal to the frequency band of the guaranteed panoramic view P, is formed on the screen of the indicator 3. In this panorama, the workload of the investigated range is estimated character of the received signals and their frequency parameters are analyzed (analyzed). Due to the randomness of the arrival times of the signals to the device input, the image of the shortcuts of the shortened video pulses on the screen of the indicator 3 is unstable (asynchronous) In order to obtain a stable image of the signal, analyze its frequencies parameters and improving the accuracy of measurements, the formation of the luminous frequency kar key mark is carried out and the raster scan is synchronized with this signal. The shortened video pulses of all received signals from the output of the N-input adder 4 to the information input of the selector 13. At the control input of the selector 13 receive strobe pulses of the same duration as the shortened video pulses Sst1 szh / Psf.- These pulses are formed using a refierator 11 and are adjusted within each line scan by delay element 10. The strobe pulses are also fed through the second video signal 12 to the luminous input of the indicator 3, forming a horizontal luminous frequency marker on the screen. Moving the mark along the line scan on the screen of the indicator 3 is performed by the same delay element 10. When the mark coincides with a certain signal on the screen of indicator 3, a temporary coincidence of the shortened video pulses of this signal occurs with the strobe pulses at the inputs of the selector 13. The selector 13 opens and synchronizes the start of the raster scan of the indicator 3. The brightness marks of the signal of the indicator 3 become stable, which allows It can carry out its time-frequency analysis and more accurate measurement of parameters, and, consequently, the accuracy of the analysis of the loading of the frequency range is improved. Claims of the Invention Multichannel receiver with N channel tiacToTHbix channels, a synchronizer, and a dial, connected in series with an A-input adder and a first video amplifier, the output of which is connected to the RC input indicator, each frequency channel contains an input bandpass amplifier, an amplitude detector and an output key , the output of which is connected to the corresponding input of the ng-input adder, and the control input is connected to the corresponding one. synchronizer output, characterized in that, in order to improve the analysis of loading of the frequency range, a sawtooth voltage generator is introduced into it, the triggering input of which is connected to the first clock output of the synchronizer, a sequentially adjustable delay element is connected between the second clock output of the synchronizer and a strobe generator and a second video amplifier, between the output of the L-input adder and the input of the vertical scan of the indicator, the horizontal scan input of which connected to the second clock output of the synchronizer, a selector is turned on, the control input of which is connected to the output of the generator of pulse pulses, a controlled oscillator is inserted into each frequency channel, the control of which is connected to the output of the sawtooth voltage generator, between the output of the input bandpass amplifier and the input of the amplitude detector are connected in series a mixer, another input of which is connected to the output of the controlled oscillator, and a compression filter, and between the output of the amplitude detector and the input m output switch connected in series N-otvodny delay element and an additional N-vhodovoy adder. Sources of information taken into account in the examination 1. The author's certificate of the USSR 807983, cl. H 03 j 7/32, 1978. 2. Martynov VA. Panoramic receivers and spectrum analyzers. M., Soz. radio, 1980, p.293, fig.8.18, (prototype).