SU1260876A1 - Device for measuring frequency selectivity of radio set by alternate receiving channels - Google Patents

Abstract

The invention relates to radio engineering. Measurement time is reduced by taking into account the maximum value of the frequency response. The device contains the source of the reference voltage 1, the trigger element 2, the trigger 3, the signal generator 4, the switches 5.1 and 5.2, the receiving and transmitting antennas 6.7, the unit for generating the level of the trimming 9, the adder 10, the amplifier II, the 3rd block 12, voltage meter 13, recorder 14, digital frequency meter 15, differentiation units 18.20 amplifier-limiter 19, lower limiter 21, (Л С

Description

electronic key 22. Subtractive amplifiers 16.1, 16.2, 16.3 were reintroduced, threshold elements 17.1, 17.2. 17.3; voltage divider 8. In storage unit 12- (therefore, in meter 13 and frequency meter 15) the level and frequency of only the greatest, i.e. global maxi "

The invention relates to radio engineering and can be used to automatically measure and record the susceptibility and frequency of the side channels of the radio electronic means.

The purpose of the invention is to reduce the measurement time by taking into account the maximum value of the amplitude-frequency characteristic.

FIG. 1 shows the structural electrical circuit of the proposed device; in fig. 2 - stress diagrams, which show his work.

A device for measuring the characteristics of the frequency selectivity of a radio receiver via side reception channels contains a source 1 of a reference voltage, a trigger element 2, a trigger 3, a signal generator 4, the first 5.1 and a second 5.2 switch, a receiving 6 and a transmitter 7 antenna, a voltage divider 8, commanding level generating unit 9, adder 10, amplifier 11, storage unit 12, voltage meter 13, recorder 14, digital frequency meter 15, first 16.1, second 16.2 and third 16.3 subtractive amplifiers, first 17.1, second 17.2 and third 17.3 threshold eleme you first differentiating unit 18, an amplifier - limiter 19, a second differentiating unit 20, the limiter 21 is coupled, the electronic key 22, the monitoring receiver 23.

The device works as follows.

The frequency of the 4 CNG generator signal is set to the lower limit, the Frequency.f of the 4 generator signal is set to the lower limit f of the range under study. On

MUMA LFC is surrounded by 01 of the reception channel. In this case, the recorder 14 registers the maximal maximum of the control voltage, cooTeeTdT-. maxims, the susceptibility of the detected secondary reception channel, and the frequency of this maximum. 2sh1.

the input of the studied radio chic 23 gives the maximum level signal maize permissible; TD1Ya its input circuits. At the initial time, the trigger 3, the first 17.1, the second 17.2 and the third 17.3 threshold elements are in the initial state, i.e. about. At the same time, on the direct outputs of the trigger 3 and the second threshold element 17.2, the voltages U) and Uj correspond to a logical zero (Fig. 2a and 2b), and on the inverse outputs of the first 17.1 and third 17.3 threshold elements

voltages U ,, and 1) 4, corresponding to logical 1 (Fig. 2c and 2g), which are fed to the control inputs of the control unit 12 and the electronic key 22. In this case,

unit 12 is in the mode of erasing information, and electronic key 22 is open. From the source 1 of the reference voltage, the closure element 2 of the trigger to the input of the trigger 3 serves

voltage Ug, which translates it to position 1. At the direct output of flip-flop 3, a voltage is generated and, corresponding to logical 1 (Fig. 2a,,) 5 which is carried out

There is a smooth change in the frequency of the signal generator 4 (built-in servo drive) in the frequency range under study f - f

When the signal frequency of the generator 4 of the signal coincides with the bandwidth of the First side reception canap, the output of the studied radio receiver 23 generates a signal 3, which is fed to the first input of the adder 10 and the noninverting input of the first subtractive amplifier 16.1, respectively, to the second and inverted, the 1st inputs are fed

On the bottom of the first

ny signal

The staggering amplifier 16.1 produces a voltage that translates the first threshold element) 7. to position 1. At the inverse of the output of the last voltage, it becomes the corresponding logical O (Fig. 2c, t-tj) and therefore the storage unit 12 is transferred to the memory mode. At the same time, at the output of the adder 10 b5, the signal is abated and which is fed to the input of the amplifier P. From its output, the amplified negative polarity Uj b (Fig. 2d, t «« t) is fed to the control input of the 4-signal generator, decreasing its output level. The level of the output signal of the 4-Signal generator is unambiguously related to the magnitude of the control voltage and, and the change in control voltage Uj and the corresponding change in the output level of the signal generator A of the signal when it is tuned in frequency correspond to the amplitude-frequency characteristic of the detected side signal. receive channel. At the same time, the voltage U from the output amplifier P is fed to the inputs: the inverting unit 12 and the First differential unit 18, as well as to the non-inverting input of the second subtractive amplifier 16.2, to the inverting input of which through the voltage divider 8 from the output of the second unit 12 is applied voltage Ulup

(where P is the non-uniformity of the amplitude-frequency characteristic of the side reception canapé, times). At the time

t, corresponding to the first local maximum of the amplitude-frequency characteristic of the detected reception channel (Fig. 2e, t "t), the output voltage of the first differentiation unit 18 changes its polarity (Fig. 2g), as a result of which two-sided limiting device suppressor 19 (fig. 2a), differentiating the second unit 20 (fig. 2i) and limiting it from the bottom limiter 21 from the bottom, a pulse G is formed (fig. 2k, t-tj), which is fed to the control input of the electronic key 22. In this case, since the electronic key 22 continues to Vc open (voltage at input U | and output U (storage unit 12 are equal to each other and

5 to f5 20 25 building 260876

at the exit

the third deductive amplifier 16.3 does not have a signal) a triggering pulse Uj is delivered to the control input of the digital frequency meter 15, which measures the frequency of the oscillator 4 corresponding to the first maximum amplitude-frequency characteristic of the side reception channel. In case of f. if the next maximum amplitude-frequency characteristic of the side reception channel is greater than the previous one (Fig. 2e), then the input Ug and output U, j of the stresses of the storage unit 12 are equal. The storage unit 12 always remembers the maximum value of the input sigils (Fig. 2e ) and therefore the measurement of the frequency of this maximum occurs. In the event that the next maximum of the amplitude-frequency

characteristics less than the previous one (Fig. 2d), then the input voltage Ue is at the input of the storage unit 12

It is less than Ue, in

9

modulo result

jg but what you get out of it

At the third subtractive amplifier 16.3, the voltage U | 2 O is applied, which translates the third threshold element 17.3 into position l. At the inverse output of the latter, the voltage U4 becomes the corresponding logical O (Fig. 2d), the electronic switch 22 closes and the trigger, the pulse U, f, does not arrive at the control input of the digital frequency 15E. Thus, in the storage unit 12 and, therefore, in the voltage meter} 3 and in the digital frequency counter 15, the level and often only the highest, i.e. the global maximum of the amplitude-frequency characteristic of the detected side reception channel. When the voltage Uj reaches the value of N / I, the output of the second subtractive amplifier 16.2 produces a voltage U (which transfers the second threshold element 17.2 to the position l. At the output of the second threshold element 17.2, the voltage Uj corresponding to logical 1 ( Fig. 2e, tt), which is fed to the control input of the registrar 14. In this case, the recorder 14 registers the maximum maximum of the control voltage,

corresponding to the maximum voem-i susceptibility of the detected side reception channel, and the frequency of this maximum. When the oscillator -4 frequency of the signal from the rfponyc-band of the detected side reception channel at the output of the first subtractive amplifier 16.1 leaves the voltage W becomes less than zero, therefore the first threshold element 17.1 returns to its initial state O, At the inverse output of the latter it produces a voltage U corresponding to -. logical 1 (Fig. 2c), which is fed to the control input of the storage unit 12, and the information stored therein is erased.

When the frequency of the oscillator 4 signal coincides with the bandwidth of the next side reception channel, the whole process repeats. When the upper frequency f of the studied range from the terminal of the generator 4 switch to the corresponding input of trigger 3 is reached, the voltage U is applied, which returns it to the initial state of O. On the forward course of the trigger 3, the voltage - O (Fig. 2a), and the restructuring, and hence the measurement process, is terminated.

Claims (1)

Formula iso.brate; neither A device for measuring the frequency selectivity characteristic of a radio receiver via side reception channels, containing a series-connected reference voltage source, trigger, trigger and signal generator, the output of the limit switch of which is connected to the second trigger input, transmitting antenna, the first switch, the movable contact of which is connected the first signal output of the generator sgsgs and the first fixed contact is connected to the input of the antenna transmission, the second switch, the first fixed to ntakt which is connected to the second fixed contact of the first switch, the second fixed contact is connected to the output of the receiving antenna as well. the input of the radio receiver under study is connected to the moving contact of the second switch 5 0 5 0 5 0 five l, a block level generation unit, the input of which is connected to the output of the radio receiver under study, a series-connected adder, the first and second codes of which are connected respectively to the outputs of the radio receiver under study and the block level generation unit, an amplifier whose output is also connected to the damage control input -: the output signal of the signal generator, the storage unit, the voltage meter and the recorder, the digital frequency meter, the output of which is connected to the second recorder input. connected in series the first differentiation unit, the input of which is connected to the amplifier output, the amplifier-limiter, the second differentiation unit and the limiter from below, characterized in that, in order to reduce the measurement time by taking into account the maximum value of the amplitude-frequency characteristic, sequentially connected the first subtractive amplifier, the non-inverting and inverting inputs of which are connected, respectively, with the outputs of the radio receiver under study and the compari level generating units The first threshold element, the inverse output of which is connected to the control input of the storage unit, is a serially connected voltage divider, the input of which is connected to the output of the storage unit, the second subtractive amplifier, the noninverting input of which is connected to the output of the amplifier and the second threshold element, my output of which is connected to the control input of the recorder, a series-connected third readout amplifier, the non-inverting and inverting inputs of which are connected respectively to the outputs of the amplifier and the storage unit, and the third threshold element, electronic key, input and control input of which are connected respectively to the output of the limiter from the bottom and inverse output of the third threshold element, and the output connected to the control input of the digital frequency meter, the second signal output of the signal generator connected to the signal input of the digital frequency meter.