SU951171A2 - Spectrum analyzer - Google Patents

Description

(54) SPECTRUM ANALYZER

one

The invention relates to a radio measuring technique and can be used for spectral sequential analysis of signals with a higher measurement rate.

A known analyzer comprising a mixer, a local oscillator, an intermediate frequency amplifier with adjustable bandwidth, a control unit, a generator and an indicator 1.

Its disadvantage is the low analysis speed, especially with the pulsed nature of the signal.

According to the main author. St. N 464851 is a known analyzer comprising a broadband path, a panoramic mixer, a narrowband path, a sawtooth generator, a local oscillator, a detector, a comparator, dividers, keys, and an indicator 2.

However, the speed of analysis is insufficient.

The goal of the image1} eteni is to increase the speed of the anal.

This goal is achieved due to the fact that a spectrum analyzer containing a series-connected broadband path, a panoramic mixer, an intermediate frequency amplifier, a filter, and an electron-beam tube, one input of which is connected to the series-connected detector and comparator, and another input connected to the generator input a sawtooth voltage to the input of the local oscillator, the output of which is connected with the second input of the panoramic mixer, as well as four keys and two voltage dividers, the outputs of each of which through two keys are connected respectively to one of the generator sawtooth voltage inputs and to the filter control input, two peak detectors, a standby multivibrator, two Schmidt triggers, a trigger and an additional key connected between the second saw blade voltage input and the standby multivibrator output are added, the input of which is connected to the output of the comparator and simultaneously with the inputs of both peak detectors, while the outputs of the peak detectors are connected to the trigger inputs via one of their Schmidt triggers, one n inputs of which is connected both to a second input standby mulgivibragora and Connectivity output the control inputs of all the keys of keys. The drawing shows a structural diagram of the analyzer. The analyzer contains a broadband path 1, a panoramic mixer 2, a narrowband path 3, which includes an intermediate frequency amplifier 4 and a filter 5. A plate of the cathode-ray tube 6 and a unit 7 for automatically adjusting the scanning frequency consisting of the detector are connected to the output of the coping-south path 3. 8 and comparator 9, whose input is connected to the starting input of the waiting multivibrator 10, as well as to the inputs of peak detectors 11 and 12. The outputs of peak detectors 11 and 12 are connected to the inputs of Schmidt trigger 13 and 14 The output of Schmidt trigger 13 Cond It is connected to the reset input of the standby multivibrator .10 and one of the inputs of the trigger 15, the second input of which is connected to the output of Schmidt trigger 14, and the output is connected to the control inputs of the keys 16-20. The voltage divider 21 is connected to the key input 19 by one of its outputs, and the second to the key input 20, whose outputs are connected to the control input of the filter 5. The voltage divider 22 is connected to the key input 17 by one of its outputs and the second to the key input 18, the outputs of which are connected to the control input of the forward stroke of the renepaiTOpa 23 sweep. The output of the waiting multivibrator 10 through the switch 16 is connected to the control input of the reverse sweep of the generator 23 of the saw-tooth voltage. The output of the sawtooth generator 23 is connected to the horizontal deviations of the electron-beam tube bis by the control input of the local oscillator 24, the output of which is connected to another input of the mixer 2. The device operates as follows. The signal under study from the output of the microwaves path 1 is fed to the input of mixer 2, to another input of which a signal comes from the output of the local oscillator 24. The intermediate frequency signal received at the output of mixer 2 is passed through a narrowband path 3 and is fed to the input of cathode ray tube 6 and the input of the automatic scanning frequency control unit 7. The sawtooth generator 23 has two modes of operation. The first mode. Accelerated scanning mode, in which reverse is possible. This mode is provided with a logical 1 at the output of the trigger 15. The second mode. Slow sweep mode (logical O at the output of trigger 15). 9 14 At the beginning of the forward stroke of the output sweep. The trigger signal 15 (logical 1) sets the maximum values of the LO frequency 24 and bandwidth by connecting the control inputs of the filter 5 and the generator 23 of the sawtooth voltage to the corresponding terminals from the dividers 21 to 22, respectively, via switches 17 and 19. Keys 18 and 20 are opposite to keys 16-18, i.e. opening for them is a logical O signal. With the pulse character of the signal being scanned and an accelerated analysis of the free parts of the range, a pulse appears at the output of the comparator 9 that triggers the waiting multivibrator 10 and incoming fia inputs of the peak detectors 11 and 12. The output pulse of the waiting multivibrator 10 through The open key 16 is fed to the reverse turn start input of the sawtooth generator 23, providing reverse sweep. After the comparator 9 returns to its initial state, the falling edge of the output pulse of Schmidt's trigger 13, formed from the output signal of the peak detector 11, sets the waiting multivibrator 10 to the initial state, stopping the reversal of the sweep. The rear edge of the Schmidt trigger pulse 13 also switches the trigger 15 to the state O, which provides connection to the passband control inputs of the filter 5 and the generator 23 of the sawtooth voltage of the corresponding outputs from the voltage dividers 21 and 22 via the keys 18 and 20, respectively. This provides a mode of slower sweep of the forward stroke of the saw-tooth voltage generator 23 and the narrowing of the passband of the filter 5 to an optimum value. Peak detector 12 and Schmidt trigger 14 are designed to switch trigger 15 to the initial position after analyzing the signal response. The time constant of the peak detector 14, which exceeds the time constant of the peak detector 13, determines the time interval of the slow sweep during the analysis and after its completion. After the output signal disappears from the comparator 9, the peak detector 12 begins to discharge and, upon reaching a predetermined level, Schmidt trigger 14 operates, the output pulse of which with a falling edge switches trigger 15 to the initial state. In the process of analyzing the response of the signal from the output signal from the comparator 9, the waiting multivibrator 10 is started, the duration of the output pulse of which determines the delay time of returning to the initial state.

Claims (1)

Claim Spectrum analyzer by ed. St. No. 464851, characterized in that, in order to increase the analysis speed, two peak detectors, a waiting multivibrator, two Schmidt triggers, a trigger and an additional key connected between the second input of the sawtooth voltage generator and the output of the waiting multivibrator, the input of which is connected to the output of the comparator and simultaneously with the inputs of both peak detectors, while the outputs of the peak detectors through their Schmidt triggers are connected to the trigger inputs, one of the inputs of which is simultaneously connected to the second input th one-shot, and the output is connected to the control inputs of all keys.