SU892342A1 - Device for measuring amplitude-phase distribution in multi-channel system - Google Patents

Description

A disadvantage of the known device also lies in the high accuracy of measuring the parameters of high-frequency signals. Indeed, the principal feature of measuring the amplitude-phase distribution in a multichannel system {in phased antenna array feeders, in antenna apertures, etc.) using known devices is the transmission of a high-frequency signal (measured or reference) through a transmission line to the measuring circuit . The amplitude phase distortion of the signals in the communication lines is the main cause of measurement inaccuracy. Thus, for example, the electric length of the coaxial cable varies within .10 -10, while it is measured in a multi-channel system with large electrical dimensions of 2 "and the stability of the electrical length of about 10 is necessary. When measuring weak signals, high-frequency signal distortion may also occur due to external interference, the field. With an increase in the geometrical dimensions of the multichannel system, the geometric length of the transmission lines of high-frequency signals increases, which leads to a significant attenuation of the signal's 61 MPLITES and narrowing of the dynamic range at the receiving end.

These drawbacks lead to a decrease in the accuracy of measuring the amplitude-phase distribution in a multichannel system.

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

The goal is achieved by the fact that in the device containing an amplitude gauge F.az, whose output is connected by a transmission line to one input of a digital information processing node, amplitude and phase meters are added, the total number of which depends on the number of measurement channels and in. which are connected by transmission lines with other inputs of the digital information processing node, while the inputs of each of the amplitude and phase meters are connected to two adjacent channels.

In addition, the amplitude and phase meter consists of three rectifiers, an analog-frequency converter and two addition blocks, the first inputs of which are connected to the first input of the amplitude and-phases meter and the first rectifier input, the second input of the first addition block, is connected to the second through the phase shifting element the input of another addition unit and the second input of the amplitude and phase meter, and the outputs of the addition units are connected to the inputs of other rectifiers whose outputs are connected to the inputs of the analog-to-frequency converter.

In this case, the converter contains three comparators, the first inputs of which are connected to the inputs of the analog frequency converter, and the second inputs are connected to the output of the low-pass filter, the input of which is connected to the output of the first digital-frequency converter, and the enabling inputs of other digital-frequency converters are connected to the outputs of the comparators, at the same time, the counting inputs of digital-to-frequency converters are connected to the output of a square-wave generator.

At that, the digital information processing unit consists of a calculator, the inputs of which are connected to the outputs of the digital signal conversion unit.

The digital signal conversion unit contains counters, the counting inputs of which are connected to the inputs of the digital signal conversion unit, and the enable inputs are connected to the output of the square pulse generator.

The drawing shows a diagram of a device for measuring the amplitude-phase distribution in a multichannel system.

The device contains a meter 1-1-1-p amplitudes and phases, transmission lines 2-1-2p, digital information processing unit 3, channels 4-1-4-p, rectifiers 5,6,7, analog-frequency converter 8, addition blocks 9 and 10, phase shifting element 11, comparators 12,13,14, low-frequency filter 15, digital-to-frequency converters 16-19, 20 square pulse generator, calculator 21, digital signal conversion unit 22, counters 23-1-23-n, 24 square pulse generator.

A device for measuring the amplitude-phase distribution in a multichannel system works as follows. .

A feature of measuring the amplitude-phase distribution in channels 4-1-4-n using the proposed device is the absence of transmission lines of high-frequency signals. The amplitudes and phase relationships of the signals in channels 4-1-4-p are measured by measuring l-1-ln amplitudes and phases, the inputs of each of which are connected directly to two adjacent channels 4. Thus, as a result of measuring the output of each meter The l-1-ln amplitudes and phases show information about the amplitude of the signal in channel 4 connected to the first., input of meter 1 and the phase ratio of the signals in this channel and its adjacent channel.; This information is in the form of a sequence of pulses equal to duration, number cat For a fixed time interval, proportional to the measured values from the outputs of the l-1-l amplitudes and phases on the 2-1-2-p transmission line is fed to the counting inputs of 23-1-23-l counters, to the enabling inputs of which comes from the generator 24 pulses of impulses, the duration of which corresponds to a known time interval. Thus, at the outputs of the counters 23-1-23-n, information about measurements in the form of binary numbers appears, which is fed to the inputs of the calculator 21. It processes the received information and records the results of the processed measurements to various recording devices.

Meter 1 amplitude and phase works as follows.

In blocks 9 and 10, the addition of two high-frequency signals from two adjacent channels 4 occurs. The high-frequency signal from one channel 4, as well as the resulting signals from blocks 9 and 10 of the addition, are converted into permanent signals using rectifiers 5,6 and then fed to the inputs of the analog frequency converter 8. The converter 8 converts these input signals into a series of pulses. Consider the operation of the meter amplitude and phase 1 in more detail. The high-frequency signal from channel 4-1 through the first input of meter 1 is fed to the input of one block of rectifier 5 and to the first inputs of the add-on blocks 9, to the second inputs of which another high-frequency signal comes from the adjacent channel 4. And on one input of the add-on block 9 This signal comes with a known phase shift, which is carried out on the phase-shifting element 11. In addition blocks 9 and 10, two high-frequency signals are added together and the resulting signals from addition blocks 9 and 10 are fed to the inputs of two other rectifiers bb and 7 Each rectifier converts a high-frequency signal into a constant signal of equal amplitude. These signals are sent to the first inputs of the comparators 12-14, to the second inputs of which the reference voltage is supplied from the output of the low-frequency filter 15. The magnitude of the reference voltage varies with the frequency of the pulses coming from the output of the first digital frequency converter 16. The frequency of the pulses of all digital-to-frequency converters 16-19 increases linearly with the arrival of the pulses from the square pulse generator 20 at their counting inputs, according to this linearly increases the value of the reference voltage. When the amplitudes of the signals from the outputs of the rectifiers 5-7 and the reference voltage are equal, the corresponding comparator is triggered and the output signal is removed from its output to the corresponding input of the D / A converter. The frequency of the pulses at the output of this digital-to-frequency converter is fixed and becomes the corresponding amplitude of the high-frequency signal sent to the input of the corresponding rectifier. At the receiving end of the 2-1-2-p transmission line, the number of pulses in the counter 23-1-2-3-p is counted.

5 times determined by the generator, i.e. The frequency of the pulses is converted into a digital code, which is necessary for input into the calculator 21.

0

The amplitudes of the measured high-frequency signals in the channels 4-1-4-p connected to the first inputs of the meters 1-1-1 -p amplitudes and phases are determined directly in these meters and in the pulse count

5 arrive in transmission lines 2-1-2-n, and in block 22, the conversion of digital signals is only converted into a digital code. The phase shift between the signals in the adjacent channels is determined by the computer in the computing device according to the measured values of the four amplitudes A, AP, Ajf A4f associated with the following equations

+ A / i.

 A1

(one)

IA, e

1A, rH

+) 1 A (2)

where a and a o are the amplitudes of the signals in

0

first and second adjacent channels

f-ii l phase signals in the first and second adjacent channels 4;

YN - phase shift signal

5 from the second channel 4, which is provided by the phase-shifting element 11;

A and A

total amplitudes

0 signals at the outputs of the add blocks.

Solving equations (1) and (2) gives the following values of the phase difference of signals in channels 4

,

1 - CH2 - ± arccos (3)

2A

A -AJJ-A |

(four)

, - (V th) .arccos 2-dd-

The known phase shift is defined by the phase-shifting element 11, whereby the calculations using forms 3 and 4 in the calculator 21 allow to unambiguously determine the phase shifts between adjacent channels. Attention should be paid to the features of the measurement in this device. To determine the phase shifts of signals in adjacent channels 4, information is used on the amplitude of these signals from neighboring amplitude and phase meters l ± l, i.e. in one meter 1. the amplitude and ish of a single signal is determined. This allows to realize the meter 1 in the proposed device in the form of a 10-pole cell. Secondly, the transmission of signals along the 2-1-2-p transmission lines in a pulse-frequency mode provides a high noise immunity of signals and a minimum number of transmission lines. These features, which are determined by the combination of features given in the claims, clarify and develop the features of clause 1 and serve the achievement of the single object of the invention to improve measurement accuracy. The connection of the meters 1 directly to the channels 4-1-4-4 (the absence of the reference channel and yy, the measurement results in the pulse-frequency mode, and their subsequent processing into the calculator 21 determine the positive effect of the whole device.

The application of the present invention allows the creation of a system for controlling the amplitude-phase distribution in multichannel microwave systems, for example, in feeders of phased antenna arrays. Parallel acquisition of information, the absence of high-frequency signal transmission lines and the processing of measurement results in a computing device provide high measurement accuracy in comparison with known devices.

The application of the proposed device allows reducing a significant amount of time in setting up and adjusting multichannel systems, quickly and automatically controlling the amplitude-phase distribution and determining faults in the channels of microwave systems.

Claims (5)

1. An apparatus for measuring amplitude-phase distribution in a multichannel system, comprising an amplitude and phase meter whose output is connected by a transmission line to one input of a digital information processing node, characterized in that, in order to improve the accuracy meters, amplitudes and phases meters, the number of which depends on the number of measurement channels, and whose outputs are connected to the digital information processing node with the transmission lines, and the inputs of each of the amplitude and phase meters are connected to two adjacent channels. , 2. A device according to claim 1, wherein the amplitude and phase meter consists of three rectifiers, an analog-frequency converter and two addition units, the first inputs of which are from the first input of the ammeter and the input of the first rectifier, the second input of the first addition unit is connected via a phase-shifting element to the second input of another addition unit and the second input of the amplitude and phase meter, and the outputs of the addition units are connected to the inputs of the remaining rectifiers whose outputs are connected to the inputs of the analog-often tnnogo converter. 3. The device according to claim 2, of t l ich i th y. This is because the analog-to-frequency converter contains three comparators, the first inputs of which are connected to the inputs of the analog-frequency converter, and the second inputs are connected to the output of a low-frequency filter, the input of which is connected to the output of the first digital-frequency converter, while enabling inputs other diffraction frequency converters are connected to the outputs of the comparators, and the counting inputs of the diFro-frequency converters are connected to the output of the rectangular pulse generator. 4. The device according to claims 1.2, which is different in that the digital information processing unit consists of a signal converting unit and a calculator, the inputs of which are connected to the outputs of said unit. 5. The device according to claim 4, wherein the digital signal conversion unit contains counters, the enabling inputs of which are connected to the output of the square pulse generator, and the counting inputs to the inputs of the digital signal conversion unit. Sources of information taken into account in the examination 1.Bahrah D.D. and others. Holography in microwave technology. M., Soviet Radio, 1979, p. 147, fig.51. 2. Goldberg I.E. et al. Complex of equipment for determining antenna parameters by holographic methods GLI., Science, 1976, p. 56, Fig. 1