SU1357868A1 - Method of determining phase of reflection factor of microwave four-terminal network - Google Patents

Abstract

The invention relates to radio engineering and provides for the expansion of the frequency range of measurements. The method consists in using an microwave generator 1 to excite an electromagnetic wave propagating along the transmission line to the microwave link 22. 22. With the help of directional couplers (BUT) 2, 4, a portion of the power propagating from the SCB generator is transmitted. 1, and with the help of BUT 3, 5 - part of the power reflected from the investigated microwave quadripole 22. Signals branched BUT 2, 3 are mixed in a three-switchable BUT 6. Signals P, P with BUT 4, 5 and signals PJ, P with three-digit NO 6 detectors detectors 7-10. Then, the amplitudes of the detected signals are measured, and the phase reflection of the microwave quadrupole 22 is determined using the measured values using the formula f arcsin (Pj) / 2V p. This is done using logarithmic amplifiers 11-13, voltage dividers 14, 15, subtractors 16, 17, adder 18, anti-logarithm calculation unit 19, arcsine calculation unit 20, and signal comparison unit 21. 1 il. (L GOSYuT 77 | W SA cl eo a: 00 2G

Description

The invention relates to radio engineering, and can be used to measure the parameters of the microwave paths.

The aim of the invention is to expand the frequency range of measurements.

The drawing shows a structural electrical circuit of a device implementing the proposed method.

The method for determining the phase of the reflection coefficient of a microwave quadrupole is that, using a SEC generator, in a transmission line ending with a microwave quadrupole, an electromagnetic wave is excited, the power propagating the B line from the microwave generator by means of two taps. (R.) and

(PJ), and also, with the help of two taps, branch off a part of the power propagating in the transmission lines to the microwave generator (P, j) and (P), the signal and P

ten

15

20

corresponding P;

mixed directional coupler 2 at the first input three-directional directional. the coupler 6, and the power P of the signal at the output of the directional coupler 5 is equal to the power of the signal coming from the output of the directional coupler 3 to the second input of the three-digit directional coupler 6. This is achieved by selecting a crosstalk of the directional taps 4, 2 and 5, 3. Directional taps 2 and 3 selected with equal transient attenuation. At the output of the three-digit directional coupler 6, signals P and P are obtained. Upon detection of the microwave signal P, P, P, and P in the detector sections 7-10, signals P, P., P and P are obtained, respectively. They are converted as follows. The signal P is amplified in the logarithmic amplifier 11 and is fed to the first input of the adder 18, to the second input of which the output goes, UUU 1 tiC 1 - 1 ME JULU, JrlC 1-2 (i

UT in a three-digit directional response signal, proportional to IgP. the branch, then all four signals are detected, the amplitudes of the detected signals are measured, and from the measured values of the amplitudes of the detected signals, the phase of the reflection coefficient is calculated in accordance with the expression

Ф arcsin (P4- Р) / 2.

35 The measured values of the detector. At the output of the adder 18, a signal equal to the sum of IgP, IgPj is formed, which is fed to the input of the voltage divider 15, from which the signal equal to 1/2 (IgPj) is fed to the second input of the subtractor 17. Signals P and P are fed to the first and second inputs of subtraction unit 16, from the output of which a signal equal to P, -P is fed to the input of divider 14, where it is converted into a signal equal to (Pj) / 2. After amplification in a logarithmic amplifier 13, a signal equal to Ig L (P,) / 2j is fed to the first input of subtraction unit 17, from the output of which a signal equal to Ig r () / 2Trp7 J is fed to block 19 of the antilog calculation. From the output of block 19, a signal equal to () / 2 is fed to the input of block 20, where, after conversion, a signal proportional to arcsin

P signals

I

g

five

correspond to the values of branched masts / fn f /

G l, g

R

nosti P ,, X y,. x

The device for determining the reflection coefficient of the microwave quadrupole comprises a microwave generator 1, directional couplers 2-5, a three-digit directional coupler 6, first 7 second 8, third 9 and fourth 10 detector sections, first 11, second 12 and third 13 logarithmic amplifiers 13, first 14 and second 15 voltage dividers, first 16 and second 17 subtraction units, adder 18, anti-log calculation unit 19, arcsine calculation unit 20, signal comparison unit 21 and microwave quadrupole 22.

The device works as follows

The signal power at the output of the directional coupler 4 is equal to the power of the signal coming from the output

0

five

0

directional coupler 2 to the first input of the three-digit directional. the coupler 6, and the power P of the signal at the output of the directional coupler 5 is equal to the power of the signal coming from the output of the directional coupler 3 to the second input of the three-digit directional coupler 6. This is achieved by selecting a crosstalk of the directional taps 4, 2 and 5, 3. Directional taps 2 and 3 selected with equal transient attenuation. At the output of the three-digit directional coupler 6, signals P and P are obtained. Upon detection of the microwave signal P, P, P, and P in the detector sections 7-10, signals P, P., P and P are obtained, respectively. They are converted as follows. The signal P is amplified in a logarithmic amplifier 11 and is fed to the first input of the adder 18, the second input of which receives an output signal proportional to IgP.

The output of the adder 18 produces a signal equal to the sum of IgP, IgPj, which is fed to the input of the voltage divider 15, from which the signal equal to 1/2 (IgPj) is fed to the second input of the subtractor 17. Signals P and P are fed to the first and second inputs of subtraction unit 16, from the output of which a signal equal to P, -P is fed to the input of divider 14, where it is converted into a signal equal to (Pj) / 2. After amplification in a logarithmic amplifier 13, a signal equal to Ig L (P,) / 2j is fed to the first input of subtraction unit 17, from the output of which a signal equal to Ig r () / 2Trp7 J is fed to block 19 of the antilog calculation. From the output of block 19, a signal equal to () / 2 is fed to the input of block 20, where, after conversion, a signal proportional to arcsin

(P4-Pz / 2 1 / P / P7, goes to signal comparison unit 21, where it is compared with the signal obtained when the device is in calibration mode. Calibration mode is performed by using the microwave short-circuit as a microwave quadripole. As a signal comparison unit 21, you can use an indicator unit of a panoramic PJ SWR meter, which allows you to automate the measurement process

313578684

phase in a wide band of working hours-detection, distinguished by that specified by the sweep band so that, in order to expand

Microwave generator 1. frequency range, optional

the powers P and P are proportional to the proportional formula of the invention; the sonals of the incident and

A method for determining the coefficient-reflected phase of a transmission line,

The reflections of the microwave quadrupole, which are mixed in a three decibel

consisting in excitation in a linearly directed coupler, detect

the transmissions loaded by the test determine the phase f of the coefficient from g

Microwave quadripole, electromagnet-microwave microwave quadrupole on the form wave, power allocation Romule

and Ru, proportional to the falling and

rashennye waves in the transmission line, and Ф arcsin l () / 2,.

Claims (1)

SUMMARY OF THE INVENTION A method for determining the phase of the reflection coefficient of a microwave four-port network, which consists in exciting in an transmission line loaded with a studied microwave four-port network an electromagnet wave, extracting powers P and P ₂ proportional to the incident and reflected waves in the transmission line, and detecting different I in that in order to extend the frequency range, further allocate power P _r and P _4, $ proportions tional respectively the incident and reflected waves on the transmission line, which is mixed in trehdetsibel SG directional coupler, detected and the phase of the reflection coefficient f microwave quadripole formula Ф = arcs in С (Р ₄ -Р ₃ ) / 2 ί / ρ _ή · Р ₂ ].