Effect of Sample Preparation on Microwave Material Characterization by Loaded Waveguide Technique
Microwave material characterization is an important nondestructive evaluation tool, as many physical and chemical properties can be related to a material's dielectric properties. These properties can be measured using a number of methods including the loaded waveguide technique. This method requires that a sample be placed in a waveguide sample holder and subsequently utilizes measured complex reflection (S11) and transmission (S21) properties to calculate the sample's dielectric properties. As such, it is important that the sample be prepared carefully, as the dielectric property calculation assumes a perfect (ideal) sample geometry. However, in practice, samples are oftentimes prepared by hand, resulting in a distorted sample geometry. This paper presents a simulation and measurement study on a number of potential sample preparation errors and the effect of these errors on calculated dielectric properties. Finally, a statistical analysis (including mean, standard deviation, coefficient of variation, and confidence interval) was applied to provide a method by which calculated dielectric properties (even when imperfect samples are used) can be checked to ensure that proper accuracy of the results has been achieved.
A. Foudazi and K. M. Donnell, "Effect of Sample Preparation on Microwave Material Characterization by Loaded Waveguide Technique," IEEE Transactions on Instrumentation and Measurement, vol. 65, no. 7, pp. 1669-1677, Institute of Electrical and Electronics Engineers (IEEE), Jul 2016.
The definitive version is available at https://doi.org/10.1109/TIM.2016.2540840
Electrical and Computer Engineering
Keywords and Phrases
Characterization; Microwave measurement; Nondestructive examination; Waveguides, Coefficient of variation; Complex reflection; Confidence interval; Microwave materials; Non-destructive evaluation tools; Physical and chemical properties; Simulations and measurements; Standard deviation, Dielectric properties; Loaded waveguide technique; Material characterization; Measurement error; Microwave nondestructive testing; Sample preparation; Statistical analysis
International Standard Serial Number (ISSN)
Article - Journal
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