SU1357869A1 - Method of checking reflectometer - Google Patents

Abstract

The invention relates to a measurement technique and provides improved verification accuracy. The device implementing the method contains r-1, a power divider 2, a variable attenuator (A) 3, a measuring A 4 and a calibrated reflectometer (PR) 5. As an exemplary measure, a portion of the input signal with a calibrated level, k- The ruy is fed to the output of PR 5. This simulates a wave reflected from the load. This allows not to use for measuring precision measuring A, for example, polarization, the accuracy of which is higher than the accuracy of the existing model loads, especially in the KB part of the millimeter range. 1 PC. with ate vj cx O5 SB

Description

The invention relates to a technique for measuring at ultrahigh frequencies and can be used to calibrate OTDRs and other VSWR meters, as well as to certify short circuits and loads.

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

The drawing shows the structure of the electrical circuit of the device that implements the method of calibration of the reflectometer.

The device contains a generator 1, a power divider 2, a variable 3 and a measuring 4 attenuator, and a rotatable reflectometer 5.

Testing of the reflectometer 5 is made as follows.

Set the attenuation of the measuring attenuator 4 to the minimum, equalize the amplitude of the signal at its output with the amplitude of the signal at the output of the variable attenuator 3, adjust the attenuation of the latter, connect the variable attenuator 3 to the input, and measure the attenuator 4 to the output of the OTDR 5, set the differential the attenuation of the measuring attenuator 4 is equal to 2nigr, where G is the value of the reflection coefficient, specified during calibration, the reading d of the calibrated reflectometer 5 is determined and its relative depth is calculated Resolve CP 100%

without taking into account the error due to the finite directivity of the coupler, then instead of the measuring attenuator 4, the matched load is connected to the output of the calibrated reflectometer and its indication is determined, which determines the error due to the finite directivity of the responder.

When certifying the short circuit (load), first to the output of the reflectometer 5 instead of the measuring attenuator. Ator 4 connect a certified shorting device (load), fixing

Editor 0. Head

Compiled by M.Kromin Tehred A. Kravchuk

Order 5994/45 Circulation 730 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

five

about 5 q 5

Q

five

The OTDR reading is 5, then measurement attenuator 4 is connected to its output and its attenuation is changed until the previous reading is obtained. The reflection coefficient of the short circuit (load) to be certified is determined by the formula G where A is the introduced attenuation of the measuring attenuator 4.

In the OTDR calibration method, instead of a load with a known reflection coefficient value, a portion of the input signal with a calibrated level is used as an exemplary measure, which is fed to the output of the calibrated OTDR. This simulates a wave reflected from the load. This makes it possible to use a precision measuring attenuator for calibration of the reflectometer, for example, a polarization one, the accuracy of which is higher than the accuracy of the existing reference loads, especially in the short-wave part of the millimeter range.

Claims (1)

Invention Formula A method for checking a reflectometer based on a signal applied to the input of a calibrated reflectometer when an exemplary measure is connected to its output and comparing the indications of a calibrated reflectometer with a known reflectance of an exemplary measure, t m and h, so that In order to improve the accuracy of verification, a signal coherent with the signal supplied to the input of a turnable tomometer is used as an exemplary measure, while its magnitude is pre-equalized with the signal size given by the input of the turnable reflectometer, and This is then reduced by a factor of 1 / G, where G is the given reflection coefficient, and its error is determined from the difference in the readings of the reflectometer being scanned. Proofreader G. Reshetnik