Calibration-Free Time-Domain Free-Space Permittivity Extraction Technique

Abstract

A time-domain free-space technique has been proposed to extract relative permittivity ( $\varepsilon _{r}$ ) and effective conductivity ( $\sigma _{e}$ ) of low-loss dielectric samples using their metal- and air-backed calibration-free reflected powers. Numerical computations and 3-D electromagnetic simulations were performed to validate the method. A sensitivity analysis was carried out to examine its accuracy. Calibration-free time-domain free-space measurements over 1–12 GHz were conducted by VNA to extract $\varepsilon _{r}$ and $\sigma _{e}$ of polyethylene and polypropylene low-loss samples.