Characterizing the Complex Permittivities of Dielectric Materials for Various Applications
Hsien Wen Chao1*
1Physics, National Tsing Hua University, Hsinchu, Taiwan
* Presenter:Hsien Wen Chao,
We proposed a method to characterize the complex permittivities of samples based on the enhancement of the electric field strength. This method can determine a very wide-range permittivity (1~1000). The method is superior in accuracy as compared with the traditional cavity perturbation technique. In addition, the imaginary part of the complex permittivity of lossy dielectric material is large and couples with its real part. The resonant frequency of a cavity with the sample depends not only on the real part of the complex permittivity of the sample but also the imaginary part, resulting in serious ambiguity in determining the sample’s complex permittivity. This work proposes a contour mapping method to determine the complex permittivity. The full-wave simulation gives us the contours of the resonant frequency and the quality factor, which are functions of the relative dielectric constant and the loss tangent. Those materials can be applied, such as bulk and liquid, but some materials are very difficult to manufacture a fixed size, such as powder and fiber.This effective medium technique (extrapolated) method can assist to evaluate their complex permittivities. The knowledge of complex permittivities in those materials can help us to design the equipment in the application of differential disciplines and industries.

Keywords: complex permittivity, lossy dielectric material, contour mapping method