SU1282342A1 - Device for measuring rectangularity coefficient of amplitude-frequency response of radio receivers - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to improve the accuracy and reduce the measurement time of the coefficient of the square wave frequency response of radio receivers. The device contains r-r 1 signals HF, attenuator 2, two amplitude modulators 3.1 and 3.2, block 4 signal matching, radio receiver under study (RI) 5, amplitude comparator 6, RS-flip-flop 7, r-r 8 signals of the low frequency, divider 9 frequencies, amplitude detector 10, reference signal generator 11, trigger unit 12, two electronic counters (C) 13.1 and 13.2, digital divider (CD) 14, indicator 15, two band-pass filters 16.1 and 16.2, differentiation block 17, Two electronic keys 18.1 and 18.2 and two electronic keys 19.1 and 19.2. The goal is achieved by counting C 13.1 and 13.2 of the number of oscillations n-f and ri f, r-8 when O reaches the upper limit of the bandwidth of IRP-5 at levels of 3 dB and 60 dB, respectively. The results of the calculation of C 13.1 and 13.2 are transmitted to the CSD 14. CSD 14 generates the result of the ratio K pf / p - f, equal to, more than 5 "coefficient. the squares that you see on the indicator board 15. 2 Il. y 00 k with 4 N5

Description

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The invention relates to radio equipment and can be used for automatic measurement and control of the square-to-square coefficient of the amplitude-frequency characteristic of radio receivers when solving problems of the electronic-magnetic compatibility of electronic devices.

The purpose of the invention is to increase the accuracy and shorten the time of measuring the rectangular factor of the amplitude-frequency characteristic of the receivers.

Figure 1 shows the structural electrical circuit diagram of the device for. measurements of the coefficient of the square of the amplitude-frequency characteristics of radio receivers; Fig. 2 shows stress plots showing the operation of the device.

A device for measuring the square-to-square ratio of the amplitude-frequency characteristics of radio receivers includes a generator of high-frequency signals 1, an attenuator 2, first and second amplitude modes; tiers 3.1 and 3.2, a signal matching unit 4, made, for example, in the form of a high-frequency tee and connected to the radio receiver 5 under study, amplitude comparator 6, RS flip-flop 7, low frequency signal generator 8, frequency divider 9, amplitude detector 1-0, reference signal generator 11, trigger unit 12, made, for example, as a single pulse generator, first and second electronic counters 13.1 and 13.2, digital divider 14, indicator 15, first and second bandpass filters 16.1 and 16.2, differentiation unit 17, first and second electronic keys 18.1 and 18.2, first and second rectifiers 19.1 and 19.2.

The device works as follows. .

The frequency of the high frequency generator 1 is set at the limit of 60 dB beyond the lower limit of the passband of the radio receiver 5 under study. Using an attenuator 2, a low-frequency signal generator 8, a frequency divider 9 and first and second amplitude modulators 3.1 and 3.2 at the inputs of the signal matching unit 4 are formed at levels 3 and 60 dB relative to the sensitivity of the test 12823422

go radio 5

amplitude signals

JO

15

20

25

multiples of the frequency of signals.

At the initial moment, the trigger 7 is found by O. At this output, it generates a magnetic O, which is built into the water generator, mechanically converts the frequency tuning to pa 1. The unit 12 is converted into 1 position and using the smooth n generator 1 to the top of the frequency.

Upon reaching the lower limit of the lower limit of neither the investigated pa (Fig. 2 a, f fyjg) at its output, a form is compared to the Od of the former 11 and produces a 6 s f ° f I,) 3 on the comparator

But also

the detector 10 generates a signal envelope

through the front page

tuned to first generator 8,

. nor and (figure 2, f

35 to the first rectifier de rectifier 19.1 voltage U (fig. Enters the control electronic key

0 tron key 18.1 for the new electronic account enters the count p. generator 8 with frequency.

 5 When reaching the bottom of the lower limit of either the investigated pa (figure 2 a, f f ..,)

n 3

at the output of the second p 50 16.2, tuned by the second amplitude 3.2, generating the envelope of the moduli X (fig.2 d, f f 55 steps into the output of the output voltage of the rectifier voltage U (fig. tron key 18.2 s

thirty

go radio 5

amplitude signals X and X- „

3 6О

five

0

five

modulated

with

multiples in frequency of the envelopes of these signals.

At the initial moment of time, RS-flip-flop 7 is in the state of logical O. In this case, its forward output produces a voltage of logical O, which is fed to the servo drive built into generator 1, mechanically connected to the frequency knob of this generator 1. Block 12 the start of the RS flip-flop 7 is shifted to the position of logical 1 and the servo drive is used to smoothly tune the frequency of the generator 1 to the upper limit of its frequency.

When the frequency of the generator 1 reaches the lower limit of the passband of the radio receiver 5 under study (Fig. 2 a, f fyjg) at a level of 60 dB, a signal Y is generated at its output, which is then compared to the level U of the driver 11 of the reference signal and generates a signal at the output of the amplitude comparator 6 DU (Fig.2 b, f ° f I,) 3 at the output of the amplitude

But also

detector 10 generates a voltage envelope voltage that

through the first band-pass filter 16.1,

tuned to the first harmonic frequency of the generator 8, in the form of a voltage. nor and (figure 2, f) comes

5 to the first rectifier 19.1. At the output of the rectifier 19.1, a voltage U is generated (Fig. 2 g), which is fed to the control input of the first electronic switch 18.1. The electronic key 18.1 is opened and the first electronic counter 13.1 counts the number of oscillations p. Generator 8 low frequency signals.

 5 When the frequency of the generator 1 reaches the lower limit of the passband of the radio receiver 5 under study (FIG. 2 a, f f ..) at the level of 3 dB

n 3

At the output of the second band-pass filter 0 16.2, tuned to the modulation frequency of the second amplitude modulator 3.2, the voltage U is generated by the envelope of the modulated signal X (Fig.2 d, f), which is fed to the input of the rectifier 19.2. Mettel 19.2 produces a voltage U (Fig. 2 e), the second electronic switch 18.2 is activated and the second

The electronic counter 13.2 also calculates the number of oscillations n f J of generator 8.

When the frequency of the generator 1 reaches the upper limit of the passband of the radio receiver 5 under study (Fig.2 a, f fgj) at the level of 3 dB, the voltage U disappears at the output of the second band-pass filter 16.2, and

fO

15

The second electronic switch 18.2 is closed, and when the frequency of the signal generator 1 coincides with the upper bandwidth of the investigated receiver 5 at the level of 60 dB, the voltage U decreases at the output of the first band-pass filter 16.1 and the first electronic switch 13.1 also closes. At the same time, the voltage Y at the output of the studied radio receiver 5 becomes minimal and at the output aMnnHTy; jHoro of the comparator 6, the voltage uY takes the value of logical O (Fig. 2 b, f 660 The jump of the voltage uY is differentiated (Fig. 2, f,) and in the form of a pulse U, - a post

drink

It goes to the control inputs of electronic counters 13.1 and 13.2 of the digital divider 14 and the R input of the RS flip-flop 7. Results of the electronic counters 13.1

20

7-25

35

It is connected to the output of the amplitude detector, a second rectifier, a second electronic key, a second electronic counter, the control input of which is connected to the output of the differentiation unit, and the output connected to the second

and 13.2 are transmitted to a digital split-30 second band-pass filter, the input of which is .14, and the electronic counters 13.1 and 13.2 return to their original state. The result of the relationship K p / p. which produces a digital divider 14, is displayed on the display of the indicator 15.

the input of the digital divider, the subsequent formula of the invention, an intimately connected low frequency signal generator, the output of which

A device for measuring the coefficient-40 is connected to other inputs of the first rectangle of the amplitude-frequency characteristic of the radio receivers, containing a serially connected triggering unit, an RS flip-flop, a high-frequency signal generator and an attenuator, sequentially connecting electronic keys and modulating the input of the first amplitude 1st modulator, the frequency divider and the second amplitude modulator, the information 45: mating input is connected to the output of the high signal generator

reference driver, amplitude comparator, to another

15

s

20

25

The input of which is connected to the output of the radio receiver under study, and the differentiation unit 4), the output of which is connected to the R input of the RS flip-flop, are connected in series to a digital divider, the control input of which is connected to the output of the differentiation unit, and It is so that, in order to increase the accuracy and reduce the measurement time of the coefficient of pro-angularity of the amplitude-frequency characteristic of radio receivers, the first-amplitude modulator connected in series, informational: the input Connected to the output of the attenuator, and a signal conditioning unit, the output of which is connected to the input of the radio receiver under study, successively connects an amplitude detector whose input is connected to another output of the radio receiver being investigated; the first band pass switch, the first rectifier, the first electronic key and the first electronic counter, the control input of which is connected to the output of the differentiation unit, and the output connected to the first input of the digital divider connected in series

It is connected to the output of the amplitude detector, a second rectifier, a second electronic key, a second electronic counter, the control input of which is connected to the output of the differentiation unit, and the output connected to the second

the second band-pass filter, the input of which

40 is connected to the other inputs of the first and

the second electronic switches and to the modulating input of the first amplitude 1st modulator, a frequency divider and a second amplitude modulator, the information input 45 of which is connected to the output of the high signal generator

frequency, and the output is connected to the second input of the signal matching unit.

Claims (1)

Claim A device for measuring the coefficient 40th input of which the output of the studied radio receiver is connected, and a differentiation unit, the output of which is connected to the R-input of the RS-trigger, a digital divider connected in series, the control input of which is connected to the output of the differentiation unit, and an indicator, moreover, in order to increase the accuracy and reduce the time of measuring the squareness coefficient of the amplitude-frequency characteristics of the radio receivers, the first amplitude modulator is connected in series information, the input of which is connected to the output of the attenuator, and a signal matching unit, the output of which is connected to the input of the studied radio receiver, a series-connected amplitude detector, the input of which is connected to another output of the studied radio receiver; the first bandpass filter, the first rectifier, the first electronic switch and the first electronic 'counter, the control input of which is connected to the output of the differentiation unit, and the output is connected to the first input of the digital divider, connected in series to the second bandpass filter, the input of which is connected to the output of the amplitude detector, the second rectifier , a second electronic key, a second electronic counter, the control input of which is connected to the output of the differentiation unit, and the output is connected to the second input of the digital divider, a separately connected low-frequency signal generator, the output of which is connected to other inputs of the first and square rectangular frequency response of the radio receivers, containing sequentially connected trigger unit, RS-flip-flop, high-frequency signal generator and attenuator, series-connected reference signal shaper , an amplitude comparator, to another second electronic switch and to the modulating input of the first amplitude modulator, a frequency divider and a second amplitude modulator, infor 45 whose input is connected to the output of the high-frequency signal generator, and the output is connected to the second input of the signal matching unit. i 1282342