SU1401404A1 - Apparatus for measuring the parameters of dielectrics - Google Patents

Abstract

This invention relates to a measurement technique. The purpose of the invention is to increase the sensitivity and expand the range of measured thicknesses, providing measurements in the frequency range. The device contains mirrors 1, made cylindrical, forming an open resonator, hollow conductive cylinders (PPC) 2 with longitudinal slots 3 oriented other to others. The distance h between PPC 2 can vary. The axes of the FPC 2 are parallel to the straight line shaped mirrors 1 and lie in a plane passing through the centers of symmetry of the mirrors 1. Compared with the known device, an increase in sensitivity of at least 100 times has been achieved, the measurement range of thickness x has been expanded by more than an order of magnitude. It is possible to measure both at a fixed frequency and with a change in frequency over a wide range, which expands the field of application of the device to increases the accuracy of measurements, since it allows one to choose the optimal one. measurement technique. The possibility of restructuring the resonator in combination with a high quality factor makes it possible to use the device for tolerance control of the diel, permeability. 1 hp f-ly, 1 ill. ABOUT)

Description

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ABOUT

The invention relates to a measurement technique, namely, devices for measuring the dielectric constant of materials, e.g. sheet-shaped.

The purpose of the invention is to increase the sensitivity and expand the range of thickness measuring, provide measurements in the frequency range,

The drawing shows the structure of a device for measuring parameters of dielectrics.

A device for measuring dielectric parameters contains mirrors 1, cylindrical, forming an open resonator, hollow conductive cylinders 2 with longitudinal slots 3 oriented towards each other. The distance h between hollow conducting cylinders 2 can vary, and the axes of hollow wires The cylinders 2 are parallel to the linearly shaped 1 m mirrors 1 and lie in a plane passing through the centers of symmetry of the mirrors 1.

A device for measuring the parameters of dielectrics works as follows.

With any method of exciting an open resonator formed by mirror 1, oscillations of discrete frequencies determined by the distance between the mirrors are established in it. Placing in the resonator a collinear system of cylinders 2 arranged with longitudinal gaps 3 leads to the selective interaction of (slotted) cylinders 2 with the field of an open resonator due to the pronounced resonance properties of cylinders 2,

The calculated Q of the system exceeds 10, which is a physical prerequisite for a significant increase in the floor concentration in the area between

cylinders 2,

I.

At the resonant frequency, the electrodynamic dimensions of the cylinders 2 increase, exceed the size of the caustic of the resonator, and due to the effect of the quasi dipole scatterplot at the resonant frequency, the energy is reradiated to the mirror 1 and, being in phase with the open resonator field, is concentrated in the region between the cylinders 2 The energy density is more than 400 times the energy density in an open resonator and this system is

extremely sensitive to the introduction of dielectric materials into it.

The change in the distance h between the cylinders 2 leads to a rearrangement of the resonant frequency, and the dependence is

f

TTD

 g

(one)

Q 5

about

0

Q 5

where c is the thickness of the walls of cylinders 2;

d is the linear size of the slit 3;

D is the internal diameter of the cylinders 2.

Analysis of equation (1) shows that technically feasible is the restructuring of the resonant system of cylinders 2, which determines the device’s broadband between 3-25 GHz. The distance h between cylinders 2 can vary between 0.05-40 mm, t The device allows to study both thin films and rather thick samples, and the entire range of measurements can be covered by a small number of slot cylinders (no more than three) using a single open resonator.

The sample under study can be both leafy and arbitrary in shape. In the latter case, it is possible to determine large dielectric constants due to the smaller effect of the sample. .

When a sheet sample of a dielectric with dimensions larger than 1-1C1 SCH the mirror dimensions is introduced into the region between the slit cylinders, and with the sample plane normal to the slot cylinder plane, a change in the resonance frequency is uniquely related to the sample

e A i + A-J (2 + A) 2 + A) -2 (C-A) s

And Ifl + 1n (|) 1 ln (S); (2) It d J

 1 + h / D, f f / f

where h is the sample thickness;

fp is the initial resonant frequency;

f is the resonant frequency of the system after the sample is applied. Measurements using the proposed device can be done in several ways: by determining the change in the resonant frequency when applying ma

Claims (1)

The claims 5 1. A device for measuring dielectric parameters, containing an open resonator formed by two 1Q mirrors, characterized in that, in order to increase the sensitivity and expand the range of measured thicknesses, the mirrors are cylindrical, and two hollow conductive cylinders are introduced, each of which has a longitudinal gap, while the hollow conductive cylinders are installed collinear between the mirrors and are oriented by longitudinal slots towards each other, while the axes of the hollow conductive cylinders are parallel to rkal and lie in a plane passing through the symmetry center of the mirror. 25 2. The device according to claim 1, wherein the, in order to ensure measurements in the frequency range, the hollow conductive cylinders are installed with the possibility of changing 3θ of the distance between them.