Characterizing the Electromagnetic Properties of Fiber Materials Using The Field-Enhancement Method

Yen-Ren Chen^1*, Hung-Chun Hsu¹, Wang-Cian Chen¹, Hsien-Wen Chao¹, Tsun-Hsu Chang¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Yen-Ren Chen, email:yrchen1988@gmail.com

This work presents a method that can precisely measure the complex permittivity of thin-and-long fiber materials. The material property is difficult to characterize in fibrous form because of its flexibility and small sample volume. Here we introduce a teflon shell and randomly pack the fibers into the container with different volumetric percentages. The samples are placed in a resonant cavity with strong field enhancement, and the resonant frequency and quality factor are measured by using a network analyzer. The complex permittivity can be obtained for various volume fraction by comparing with the simulation results of a full-wave solver. The effective medium technique is then employed to calculate the effective electromagnetic properties of the pure fiber materials. Measurement of the polyacrylonitrile (PAN) fibers after various processing stages will be shown.

Keywords: fiber, dielectric property, enhanced field method, frequency response, effective medium theory