SU1257544A1 - Device for measuring frquency and frquency devilation - Google Patents

Abstract

This invention relates to electrical measuring technology. It can be used to measure the frequency and frequency deviation of signals with frequency-impedance and amplitude-pulse modulation. The aim of the invention is to improve the measurement accuracy. To achieve this goal, the device contains input bus 1, attenuator 2, phase detector 3, first amplifier 4, memory block 5, controlled oscillator 6, high frequency amplifiers 7 and 11, frequency meter 8, pulse shaping unit 9, block 12 forming a channel pulse and an amplitude detector 14; a frequency detector 15, an adder 16, a switch 17 and a divider 18 are additionally introduced. The device provides an increase in the accuracy of measuring the frequency and deviation of the phase-coupled signals. 4 il. Q (L S e ate

Description

ten

The invention relates to electrical measuring equipment and can be used to measure the frequency and frequency deviation of signals with frequency-pulse or amplitude-pulse modulation.

The purpose of the invention is to improve the measurement accuracy.

FIG. 1 shows a functional diagram of the device in FIG. 2, 3 and 4 - diagrams of the output signals of the blocks of the device.

The device contains an input bus 1, an attenuator 2, a phase detector 3, a first amplifier 4, a memory block 5, a controlled oscillator 6, a high frequency amplifier 7, a frequency meter 8, a tuning pulse shaping unit 9, a key 10, a second amplifier 11, a block 12 forming a channel pulse, 20 switch 13, amplitude detector 14, frequency detector 15, adder 16, switch 17, divider 18.

In the device, input bus 1, attenuator 2, phase. Detector 3, first amplifier are connected in series

12575442

forming the channel pulse and to the input of the block 9 Normalization of the pulses of the adjustment.

In the mode of measuring pulses with 5 equal frequencies, the key 10 is open, the transit envelope pulses pass through block 9, are amplified by the second amplifier 11 and control the operation of the key in memory block 5.

The high-frequency signal is attenuated in the attenuator 2, is fed to the input of the phase detector 3. The block chain phase detector 3, amplifier 4,

memory block 5, controlled generator

15

6 and the high frequency amplifier 7 forms a phase locked loop which closes when the key is closed in memory block 5, i.e. at the time of arrival of the control pulse. When the FA11CH ring opens at the end of the control pulse, the control voltage is stored in memory block 5.

As a result, at the output of the block

25, a constant signal of the form shown in FIG. 2c, and at the output of the controlled oscillator 6 and further on the high frequency amplifier 7 a signal is formed with a constant frequency equal to the frequency of filling the pulses of the input signal (Fig. 2 g). In the mode of measuring the frequency of time-divisiond signals, the key 10 is closed (the type of input signal is shown in Fig. 3a). The envelope of the amplitude detector 14 is fed through the adder 16 to the channel pulse shaping unit 12, where the pulse sequences of each channel are selected (Fig. 3). The pulses of the measured channel, selected by the switch 13, are fed through the switch 17 to the input of the frequency divider 18, the division factor

4, block

5 memory, controlled oscillator 6, high frequency amplifier 7 whose output is connected to the second BJCO house of phase detector 3 and input iacTOTOMepa 8, In addition, frequency detector 15, accumulator 16, switch 12 forming a channel pulse, switch 13, switch 17, divider 18, key 10, trimming pulse shaping unit 9, second amplifier 11, the output of which is connected to the control input of memory unit 5. The input of the frequency detector 15 is connected to the input bus 1. The output of the amplitude detector 14 is connected to the second input of the adder 16, the output of which is connected to the second input of the switch 17 and the second input of the trimming pulse shaping unit 9.

The device works as follows.

In the mode of measuring the frequency and deviation of the amplified-modulated signal with the same frequency in all pulses of the sequence, the signal from the input bus 1 (Fig. 2a) enters the input of the attenuator 2 and the amplitude detector 14. In the latter, the signal is detected and envelope pulses (Fig. 2b) arrive through the adder 16 to the inputs of block 12

memory block 5, controlled generator

6 and the high frequency amplifier 7 forms a phase locked loop which closes when the key is closed in memory block 5, i.e. at the time of arrival of the control pulse. When the FA11CH ring opens at the end of the control pulse, the control voltage is stored in memory block 5.

As a result, at the output of the block

the memory produces a constant signal of the type shown in FIG. 2c, and at the output of the controlled oscillator 6 and further on the high frequency amplifier 7 a signal is formed with a constant frequency equal to the frequency of filling the pulses of the input signal (Fig. 2 g). In the mode of measuring the frequency of time-divisiond signals, the key 10 is closed (the type of input signal is shown in Fig. 3a). The envelope of the amplitude detector 14 is fed through the adder 16 to the channel pulse shaping unit 12, where the pulse sequences of each channel are selected (Fig. 3). The pulses of the measured channel, selected by the switch 13, are fed through the switch 17 to the input of the frequency divider 18, the division factor

it is equal to 1. Through the key 10, the pulses go to the trimming pulse shaping unit 9, where they are compared with the pulses coming from the adder 16. When both pulses coincide, a control pulse appears at the output of the circuit, which is then amplified, generated and fed to the control input memory block 5 (fig. 3g). As a result, a signal of the type shown in FIG. Rear, controlling the frequency of the controlled generator 6. Frequency

the controlled oscillator 6 is at the same time constant and corresponds to the frequency of filling the pulses of the measured channel (Fig, Ze). In the first and second cases, the output frequency of the device coming from the output of the high frequency amplifier 7 is measured by a frequency meter 8.

In the mode of measuring the frequency and frequency deviation of signals with phase coupling of carrier frequencies f and f, a sync pulse is generated in frequency detector 15 (Fig. 4 a, b). When measuring a signal without temporal separation of the channels, the switch 17 connects the output of the adder 16 to the input of the divider 18, thus disconnecting the output of the switch 13. If

f - f i ---

In block 18, the required division factor is selected, which is determined by the formula

one

where t

- the period of the clock pulses,

d - minimum measured signal deviation, determined by measurement accuracy. Wherein

  Filmer.0 T00

where f “, Mgp is the measured frequency,

О - maximum permissible measurement error,%.

After dividing by n, the pulses go through the key 10 (Fig. 4c) to the adjustment pulse shaping unit 9 and control the operation of the PLL ring (Fig. 4d) in the same way as in the cases considered.

In the mode of measuring the parameters of the signal in time-division channels, the switch 17 connects to the input of the divider 18 pulses from the switch 13, corresponding to the selected channel pulse. In this case, the division factor n must be reduced by the number of channels K that exist in this system. Then

one

p-7t; 7 the rest mode DI J K

The device has no differences from the previous ones.

5 Thus, the proposed device for measuring the carrier frequency and signal deviation allows one to measure the parameters of pulse frequency signals and to increase the accuracy of 10 measurements of phase-related carrier frequencies and deviation at these frequencies

when up to accuracy S pT

100% 15 f PKT

icmer

Claims (1)

Invention Formula A device for measuring the frequency 20 and frequency deviation, containing a serially connected input bus attenuator, a phase detector, a first amplifier, a memory unit, a controlled oscillator, a high frequency amplifier, and a frequency meter, serially connected trimming pulse shaping unit, the first input of which is connected with the output of the key, and the second amplifier, the code of which is connected 30 to the control input of the memory unit, the series-connected channel pulse shaping unit and the switching unit, as well as the amplitude de tector whose input is connected to  input bus, while the output of the high-frequency amplifier is connected to another input of the phase detector, characterized in that, in order to improve the measurement accuracy, serially connected frequency detector and adder and serially connected switch and divider, the output of which is connected to the key input, are introduced into it at 5 of this, the input of the frequency detector is connected to the input bus, the other input of the adder is connected to the output of the amplitude detector, and the output is connected to the input. channel block house Q pulse, another input of the formating block of the trimming pulses and the first input of the switch, the second input of which is connected to the output of the switch. em.2 S / 6 and sree Compiled by S. Lebedev Editor M. Petrova Tehred M. Khodanich Proofreader V. Sinitska Order 4913/43 Circulation 728 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4