Method for measuring substance dielectric constant by using monopole antenna

A technology of monopole antenna and dielectric constant, applied in the direction of measuring electrical variables, measuring resistance/reactance/impedance, measuring devices, etc., to achieve the effect of introducing small errors

Inactive Publication Date: 2009-09-09
UNIV OF SCI & TECH OF CHINA
View PDF0 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The circuit method measurement is to use the circuit to measure the capacitance of the sample to be tested. When the size of the sample is known, the relationship between the capacitance and the dielectric constant of the sample is ϵ r = ϵ ϵ 0 = Cd ϵ 0 S The dielectric constant of the substance to be measured can be obtained, and this method can only be measured for solid substances

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for measuring substance dielectric constant by using monopole antenna
  • Method for measuring substance dielectric constant by using monopole antenna
  • Method for measuring substance dielectric constant by using monopole antenna

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Implementation 1: The antenna part of the monopole antenna is immersed in the substance to be tested, and the microwave vector network analyzer sweeps and emits microwaves, and measures the resistance of the monopole antenna in the substance to be tested (this implementation takes glass medium as an example for illustration) Variation of reflection coefficient with frequency, such as figure 2 As shown in the middle curve A, a time gate can be added if necessary, such as figure 2 Shown in curve B. Depend on figure 2 The frequency f at which the maximum value of power emission can be obtained Mn (n=1, 3, 5...), namely figure 2 shown in S 11 The frequency at the minimum value, and then measure the length L of the antenna, which can be obtained by the formula ϵ = ( nc 4 L f Mn ...

Embodiment 2

[0019] Implementation 2: Using the same principle as above, first place the monopole antenna in a substance with a known dielectric constant (this implementation takes air as an example), and measure the reflection coefficient of the monopole antenna in the air as a function of frequency, as image 3 As shown in curve A in , add time gate if necessary, such as image 3 Shown in curve B. Depend on image 3 Get the reflection coefficient S in air 11 The microwave frequency f at the minimum value 0n (n=1, 3, 5...), and then the monopole antenna is immersed in the substance to be measured, and the same measurement method obtains the microwave frequency f at the minimum reflection coefficient of the substance to be measured Mn (n=1, 3, 5...) (such as figure 2 shown). by the formula (n takes the same value, n=1, 3, 5...) Calculate the dielectric constant of the substance to be measured. In this implementation, since it is known that the dielectric constant of air is 1, the ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a method for measuring substance dielectric constant by using a monopole antenna. Transmitting characteristics of the monopole antenna are used for measuring the frequency of microwave when the transmit power of the microwave is maximal in a substance to be measured. Therefore, the dielectric constant of the substance to be measured is obtained. When part length of the monopole antenna has a certain relationship with the wavelength of transmitted electromagnetic waves in the substance to be measured, the transmitting power of the antenna reaches the maximum. The monopole antenna method just uses such relationship to measure the dielectric constant. The method can measure the dielectric constant of the substance more simply and accurately.

Description

technical field [0001] The invention relates to a method for measuring the dielectric constant of a material, in particular to a method for measuring the dielectric constant of a material by using the emission characteristics of a monopole antenna in a medium. Background technique [0002] As a basic electromagnetic parameter of matter, the dielectric constant of matter needs to be measured more accurately and conveniently. The emission properties of a monopole antenna in a medium are closely related to its dielectric constant. The structure of the monopole antenna is half of the symmetrical oscillator, and the antenna is excited from the base, and its radiation lobe pattern is the same as that of the symmetrical oscillator in free space. When the length of the antenna has a certain relationship with the wavelength of the microwave, its transmission efficiency is the largest, that is, the transmission power reaches the maximum and the reflection power reaches the minimum. ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01R27/26
Inventor 王慧慧李弘李斌陈志鹏王雨后李翔尤玮
Owner UNIV OF SCI & TECH OF CHINA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap