Complex permittivity measurements using cavity perturbation technique with substrate integrated waveguide cavities

2010 ◽  
Vol 81 (6) ◽  
pp. 064704 ◽  
Author(s):  
Humberto Lobato-Morales ◽  
Alonso Corona-Chávez ◽  
D. V. B. Murthy ◽  
José L. Olvera-Cervantes
Keyword(s):  
Complex Permittivity ◽  
Perturbation Technique ◽  
Substrate Integrated Waveguide ◽  
Cavity Perturbation ◽  
Waveguide Cavities ◽  
Permittivity Measurements

scholarly journals Nondestructive, Microwave Testing of Compression Strength and Moisture Content of Green Molding Sands

2021 ◽  
Vol 40 (4) ◽  
Author(s):  
Beata Gal ◽  
Daniel Nowak
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Water Content ◽  
Compression Strength ◽  
Complex Permittivity ◽  
Perturbation Technique ◽  
Testing Method ◽  
Cavity Perturbation ◽  
Permittivity Measurements

AbstractA nondestructive microwave testing method to control the green compression strength and moisture content was proposed and demonstrated. There are various green moulding sands, both qualitative (bentonite type) and quantitative (bentonite and water content), prepared. The permittivity measurements were performed by cavity perturbation technique (CPT) at 2.45 GHz. Relative complex permittivity of the bentonite bonded moulding sands is proportional to the bentonite and moisture content and is inversely proportional to green compressive strength. It was shown that the obtained permittivity value of the molding sands be used to investigate the green compression strength and moisture content.

scholarly journals A High-Sensitivity Microfluidic Sensor Based on a Substrate Integrated Waveguide Re-Entrant Cavity for Complex Permittivity Measurement of Liquids

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4005 ◽  
Author(s):  
Zhihua Wei ◽  
Jie Huang ◽  
Jing Li ◽  
Guoqing Xu ◽  
Zongde Ju ◽  
...  
Keyword(s):  
Predictive Model ◽  
Complex Permittivity ◽  
Perturbation Technique ◽  
Microfluidic Channel ◽  
High Sensitivity ◽  
Substrate Integrated Waveguide ◽  
Debye Relaxation ◽  
Permittivity Measurement ◽  
Acetone Water ◽  
Complex Permittivity Measurement

In this study, a novel non-invasive and contactless microwave sensor using a square substrate integrated waveguide (SIW) re-entrant cavity is proposed for complex permittivity measurement of chemical solutions. The working principle of this sensor is based on cavity perturbation technique, in which the resonant properties of cavity are utilized as signatures to extract the dielectric information of liquid under test (LUT). A winding microfluidic channel is designed and embedded in the gap region of the cavity to obtain a strong interaction between the induced electric field and LUT, thus achieving a high sensitivity. Also, a mathematical predictive model which quantitatively associates the resonant properties of the sensor with the dielectric constant of LUT is developed through numerical analysis. Using this predictive model, quick and accurate extraction of the complex permittivity of LUT can be easily realized. The performance of this sensor is then experimentally validated by four pure chemicals (hexane, ethyl acetate, DMSO and water) together with a set of acetone/water mixtures in various concentrations. Experimental results demonstrate that the designed sensor is capable of characterizing the complex permittivities of various liquids with an accuracy of higher than 96.76% (compared with the theoretical values obtained by Debye relaxation equations), and it is also available for quantifying the concentration ratio of a given binary mixture.

A Permittivity Measurement Method Based on Cavity Perturbation Technique

2014 ◽  
Vol 590 ◽  
pp. 629-633 ◽  
Author(s):  
Qian Chen ◽  
Yang Yang ◽  
Ka Ma Huang ◽  
Cheng Chen ◽  
Kai Yong Wang
Keyword(s):  
Temperature Measurement ◽  
Complex Permittivity ◽  
Measurement Method ◽  
Perturbation Technique ◽  
Laboratory Method ◽  
Microwave Chemistry ◽  
Permittivity Measurement ◽  
Microwave Engineering ◽  
Measurement Results ◽  
Permittivity Measurements

Effective complex permittivity measurements of materials are important in microwave engineering and microwave chemistry. This paper describes a convenient laboratory method designed to obtain the permittivity for some materials. The hole for temperature measurement has been designed. The permittivity of materials at deferent temperature can be measured. The measurement results of the real part and imaginary part of the permittivity agree well with literature data at 2.45GHz.

Broadband complex permittivity measurements of nematic liquid crystals based on cavity perturbation method

2019 ◽  
Vol 47 (1) ◽  
pp. 89-98
Author(s):  
Chengyong Yu ◽  
En Li ◽  
Zhiyong Zhang ◽  
Xiangru Wang ◽  
Chong Gao ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Perturbation Method ◽  
Complex Permittivity ◽  
Nematic Liquid Crystals ◽  
Cavity Perturbation ◽  
Permittivity Measurements
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