SU873062A1 - Device for measuring dielectric parameters - Google Patents

Description

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The invention relates to radio measuring devices for measuring the parameters of dielectrics and can be used in electrical insulation and cable industry.

A device for measuring parameters of dielectrics is known, which contains a microwave generator connected to a waveguide tee to one arm of which a frequency meter is connected, and to the other arm is the input of a measuring path whose output is connected through a series-connected detector and an indicator to the input of a superhigh-frequency generator with lid T

However, this device does not provide high measurement accuracy and works only at one strictly fixed frequency.

The purpose of the invention is to increase the measurement accuracy and expand the frequency range. This goal is achieved by the fact that a device for measuring the parameters of dielectrics, containing an extra high-frequency generator connected to a waveguide tee, to one arm of which a frequency meter is connected, and to the other arm is a measured input. body path, the output of which is connected through a series-connected detector and indicator to the input

10 microwave generator, a resonator placed in a cryostat with a lid, the resonator is made in the form of a disk from the dielectric under investigation, installed in a cryostat on one

The 15 ends of the rod, the other end of which is fixed on the lid, and to the free ends of the measuring path are connected, respectively, two injected arcuate dielectric waves, which are electromagnetically connected to the resonator.

The drawing shows a structural electrical circuit of the device.

The device contains a microwave generator 1, a waveguide tee 2, a frequency meter 3, a measuring path 4, a detector 5, an indicator 6, a resonator 7, a cryostat 8, a switch 9, a rod 10, arc-shaped dielectric waveguides 11, nails 1

The device works as follows.

The frequency-modulated signal from the output of the microwave generator through the waveguide tee 2, the measuring path 4 enters the dielectric waveguide J1. The frequency of the microwave oscillator 1 is smoothly tuned. At the moment the oscillator 1 frequency coincides with one of the resonant frequencies of the resonator 7, oscillations occur in the latter and a pulse appears at the output of detector 5, the duration of which depends on the quality factor of the resonator under study. The pulse from the output of the detector 5 is fed to the input of the indicator 6, which is synchronized by strobe pulses. The pulse from the indicator enters the input of the generator 1, at the moment of arrival of the pulse, a generation failure occurs. The exponential envelope of the high-frequency oscillations of the resonator 7 is observed on the indicator 6. The Q-factor of the resonator 7 is determined by the value of the constant damping time, according to which the tangent of the dielectric angle from which it is made is judged.

A part of the output signal of the ultra-high-frequency generator 1 is fed to the frequency meter 3 through another waveguide tee 2. At the measured resonant frequency and the measured linear dimensions of the resonator 7, the dielectric constant of the dielectric is calculated. Decrease in re-reflection level

the internal cavity of the cryostat is achieved by using absorbers 12.

The proposed implementation of the device improves the accuracy of measuring the parameters of dielectrics in a wide frequency range with minimal radiation losses during a practically single-wave mode of operation.

Claims (1)

Invention Formula A device for measuring the parameter of dielectrics containing a microwave generator connected with a light-water tee to one arm of which a frequency meter is connected, and the other shoulder is the input of a measuring path whose output is connected via series-connected detector and indicator to the input of a microwave generator oscillator placed in a cryostat with a cover that, in order to increase the measurement accuracy and expand the frequency range, the resonator is made in the form of a disk of the studied a dielectric installed in a cryostat at one end of the rod, the other end of which is fixed to the lid, and the two ends of the arcuate dielectric waveguide connected electromagnetically to the resonator are connected to the free ends of the measuring path. , Sources of information taken into account in the examination I. Beykin A.I. et al. Installation for the study of dielectric losses and dielectric permeability at the temperature of liquid helium at ultrahigh frequencies, Metrologists, monthly application to the scientific and technical journal Measuring equipment, 1976, No. 6, pp.59-63 (prototype). iL I iil. ir i tt If Lg 54 -Asom