RU2778030C1 - Method for determining the attenuation coefficient of the feeder line - Google Patents

Abstract

FIELD: radio measurements.

SUBSTANCE: invention relates to the technique of radio measurements and is intended to determine the attenuation coefficient of the antenna-feeder line. The invention is a method for determining the attenuation coefficient of a feeder line, consisting in measuring the standing wave coefficient by the voltage of a feeder line loaded on a short-circuiter, followed by a calculated determination of the attenuation coefficient, in which, after measuring the standing wave coefficient by the voltage of a feeder line loaded on a short-circuiter, the standing wave coefficient is additionally measured by the voltage of a feeder line loaded on the agreed load, then the attenuation coefficient A of the feeder line is determined.

EFFECT: increase in measurement accuracy.

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Description

The invention relates to radio measurements and can be used in antenna-feeder technology.

There is a known method for determining the attenuation coefficient in Deschamps feeder lines [1], which includes measuring the complex reflection coefficient of the investigated feeder line loaded on a movable short-circuiter at its different positions, and determining the attenuation coefficient from the measurement results. The disadvantage of this method is its significant complexity.

The closest to the invention in technical essence is a method for determining the attenuation coefficient in feeder lines according to the Tatarinov method [1], taken as a prototype, which consists in measuring the voltage standing wave ratio (VSWR) of a short-circuited feeder line, followed by determining the attenuation coefficient A according to the formula

where K is the VSWR of the feeder line loaded on the short circuit.

The disadvantage of the prototype is that the method does not take into account the effect of inhomogeneities of the feeder line on the value of the attenuation coefficient, which leads to a large systematic error, which is the greater, the greater the value of inhomogeneities, which sharply limits the scope of the method only to well-tuned feeder lines.

The technical result of the invention is that the measurement accuracy of the attenuation coefficient of the feeder line is increased due to the reduction of the systematic measurement error, which occurs as a result of the influence of feeder line inhomogeneities on the value of the calculated attenuation coefficient. The specified technical result is achieved by the fact that when calculating the attenuation coefficient of the feeder line, in addition to the measured values of the VSWR of the feeder line loaded on the short circuit, the measured values of the VSWR of the feeder line loaded on the matched load are also used.

The proposed method is illustrated by the drawings of Fig. 1 - fig. 3.

Fig. 1 - block diagram of the attenuation coefficient measurement, where:

1 - panoramic VSWR meter R2-137/1;

2 - coaxial-waveguide transition;

3 - measured section of the waveguide path;

4 - short circuit or matched load.

Fig. 2 - the results of calculating the VSWR of the feeder line loaded with a matched load for a specific implementation of the waveguide path in the operating frequency range, where:

R - VSWR of the feeder line, loaded with a matched load;

F ^<1> - the ratio of the path length to the wavelength.

Fig. 3 - the results of calculations of numerical simulation of the process of measuring the attenuation coefficient of the same specific implementation of the waveguide path in the operating frequency range, where:

A is the measured path attenuation coefficient in dB;

Aex - path attenuation coefficient in dB, measured by the Tatarinov method;

Aexn - path attenuation coefficient in dB, measured by the proposed method;

F ^<1> - the ratio of the path length to the wavelength.

The proposed method is implemented as follows. A panoramic VSWR meter R2-137/1 is connected to the input of the measured section of the waveguide path through a coaxial wave transition, a short-circuiter is connected to the output of the measured section of the waveguide path and the VSWR is measured, then the short-circuiter is replaced with a matched load and the VSWR is measured.

The attenuation coefficient A of the feeder line is determined by the formula

where K is the VSWR of the feeder line loaded on the short circuit; R - VSWR of the feeder line loaded with a matched load at the same frequency.

It follows from the formula that at R=2, the systematic error according to the Tatarinov method is 0.5 dB.

Shown in FIG. 3 calculations show that the proposed method for measuring the attenuation coefficient, in comparison with the prototype, reduces the systematic measurement error by 10 times with an average VSWR value of the path in the operating range equal to 2.

Sources of information

1. Starikov V.D. Microwave measurement methods using a measuring line. M: Soviet radio. 1972. S. 83-85, p. 71-73.

Claims (3)

A method for determining the attenuation coefficient of the feeder line, which consists in measuring the standing wave coefficient by the voltage of the feeder line loaded on the short circuit, followed by the calculated determination of the attenuation coefficient, characterized in that, in order to increase the accuracy of measuring the attenuation coefficient of the feeder line, after measuring the standing wave coefficient by voltage of the feeder line loaded on the short circuit, the standing wave coefficient is additionally measured by the voltage of the feeder line loaded on the matched load, then the attenuation coefficient A of the feeder line is determined by the formula

, where K is the standing wave ratio for the voltage of the feeder line loaded on the short circuit; R is the standing wave ratio for the voltage of the feeder line loaded with a matched load at the same frequency.

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