SU1392516A1 - Method of determining relative measurement error of mean wave impedance of coaxial microwave transmission line - Google Patents

Abstract

This invention relates to a microwave measurement technique. The purpose of the invention is to improve the accuracy of determining the relative error of measurement of the average wave resistance (SHS) of coaxial microwave transmission lines (LPC) with losses and simplification of the method. As a SVS measure, a resistive VSWR measure with a quasi-centered H1L4I parameter is used, the nominal resistance of the direct current to the cut is equal to the nominal SVS Z of the coaxial microwave transmission line. The relative error of measurement of SHS is determined by f-le5g 8g, + 5Z,, - relative error of resistance of measurement of SHS; An additional relative error in the measurement of SHS, caused by the presence of losses in the coaxial transmission line SCCH, is determined through the design and electrical parameters of the coaxial transmission line. The use of a resistive VSWR measure, a kra, is a device with quasi-centered parameters, as an ideal measure of lossless lossless resistivity based on the fact that the signal reflected from a resistive load is equivalent in the working range to reflection from an ideal H of an infinitely long length with an average characteristic impedance equal to the resistance of a DCI resistive measure to direct current. The relative error does not exceed 10%. i cl

Description

The invention relates to a technique for measuring at microwave frequencies and can be used in the metrological testing of pulsed reflectometers (IR) based on the measurement error of the average wave resistance of coaxial microwave transmission lines.

The purpose of the invention is to improve the accuracy of determining the relative error of measurement of the average wave resistance of coaxial transmission lines. Microwave loss and simplification of the method.

The way it feels; it is done in the following way.

As a measure of the average characteristic impedance of a coaxial microwave transmission line, resistive KSBN measures are used with quasi-focused parameters and parameters, the nominal DC resistance of which is equal to the nominal average impedance of the coaxial transmission line The loss-free coaxial microwave transmission line's average wave impedance is based on the fact that the signal reflected from the resistive in the operating frequency range, the reflection from an ideal coaxial microwave transmission line without loss of infinitely long length with an average characteristic impedance equal to the resistance of the resistive measure of VSWR to direct current.

The relative error of the method for determining the measurement error of the average wave resistance of coaxial microwave transmission lines with a loss of over 10%.

The determination of the measurement error of the average wave resistance of coaxial microwave transmission lines with losses is divided into two stages.

The first stage is the determination of the weave wave resistance, take the nominal DC resistance of a resistive VSWR measure, and the total relative error SZ of measuring the average wave resistance of the coaxial microwave transmission line with losses is determined by the formula

Sz SZ, + g

de

Sz.

Sz, the relative measurement error of the average wave resistance of the coaxial transmission 40 UHF without loss; additional relative norpei iHocTb measuring the average wave

resistance, caused by 45 measurements in a given range of averages

wave impedances use a set of resistive measures VSWR.

At the second stage, an additional error is determined due to the presence of losses in the coaxial line.

The presence of a microwave in the coaxial transmission line is determined through the design and electrical parameters of the coaxial transmission line.

transmission microwave Sz, according to the formula

WITH

Z

-Vv-T-.;; P "/ G ;. -B- 5 :: R .; (0,5 - - - - - () b

OTG-4 || Zn 7, Ti III CH; | L J. L J-JJ

1 - (Z, - ZJ / (ZH + ZJ

Where

- nolnoBoi resistin

the decision to measure the average wave resistance of the coaxial microwave transmission line without loss, which is carried out when testing pulsed reflectometers. At the same time, a resistive VSWR measure is connected to the measuring input of the pulse reflectometer, the average characteristic impedance j with respect to y4acfKy of the reflected signal, corresponding to the length of the coaxial transmission line required when testing the MI, is measured, the error of variation is calculated by the formula

-.

Km

100(%),

- nominal value of resistance of resistive measure VSWR to direct current. determine the error of the microwave transmission Sz, according to the formula

ritelnoy tract:

Uo 4 ir-1U GN / m L

 r, and r,

Z is the nominal wave impedance measured by a coaxial microwave transmission line;

: - the speed of light in vacuum;

-Magnetic vacuum constant;

- length of coaxial microwave transmission line;

 - coefficient for shortening the wavelength in a coaxial microwave transmission line;

-nominal radii respectively central

and external conductors of a coaxial microwave transmission line;

R | - Pg the specific resistances of the coating materials, respectively, of the central and outer conductors of the coaxial microwave transmission line;

p, and p relative

magnetic permeability of coating materials, respectively, of the central and outer conductors of a coaxial microwave transmission line;

ROJ - linear resistances, respectively, of the central and external conductors of the coaxial microwave microwave direct current transmission line;

K - coefficients that take into account the design features of the central and external, respectively

- (i

 - rn7

the conductors of the coaxial microwave transmission line, for example, for solid conductors K, and K, j are equal to 1, for the central conductor in the form of stren1 and (twist) of n wires

to,:;

constant time approximating function.

The method of determining the measurement error of the average wave resistance of coaxial transmission lines of the SBSH with pulse reflectometers allows creating a system of metrological provision of this type of measurements and introducing into the technical characteristics of the impulse characteristics a mode of measuring the average wave resistance of the coaxial microwave transmission lines with a normalized error.

Claims (1)

30 claims five 0 five 0 five A method for determining the relative error in measuring the average wave resistance of coaxial microwave transmission lines, which consists in probing the average wave resistance by measuring a drop-like signal, determining the wave resistance of the coaxial transmission line of the microwave signal reflected from the average wave resistance signal measured from the measure SZ and losses, about the fact that, in order to improve the accuracy of determining the relative solving the measurement of the average wave resistance of a coaxial microwave transmission line with losses and simplifying the method, as a measure of the average wave resistance, use a resistive VSWR measure with quasi-focused parameters, the nominal DC resistance of the coaxial microwave transmission line, and the relative measurement error the average wave resistance of coaxial microwave transmission lines with losses is determined by the formula JZ 5Z, + SZi, Where S Zj - relative measurement error of the average Sz - .1shlp: - F-: p; F E: JL: .. J °: f:.: Ll .-: 1:: L I 1 - (ZjV (Z, + ZJ de f 47-10 15 -7 2Lf / C; r, and r, Zg - wave resistance of the measuring path. Ohm; Z is the nominal characteristic impedance of the transmission line. Ohm; 20 C is the speed of light in a vacuum;  - magnetic constant of vacuum;  - coefficient of shortening the wavelength in the coaxial microwave transmission line; length of coaxial microwave transmission line, m; nominal radii, respectively, of the central and external conductors of the coaxial microwave transmission line, mm; specific resistances of coating materials, respectively, of the central and outer conductors of a coac thirty p and pr40 wave resistance of coaxial microwave transmission lines, due to the presence of losses, and sialny microwave transmission line, Ohm (II, and (ijj, - relative magnetic permeability of coating materials, respectively, of the central and outer conductors of the coaxial microwave transmission line; five five 0 0 01 and R 02 K, and K );), Kg; (irr. -K „;) 2 - frictional DC resistances respectively and external conductors of coaxial microwave transmission line, Ohm / m; -coefficients that take into account the design features of the central and outer conductors of the coaxial microwave transmission line, respectively; - constant time approximating function.