Broadband, Stable, and Noniterative Dielectric Constant Measurement of Low-Loss Dielectric Slabs Using a Frequency-Domain Free-Space Method

A broadband, stable, and noniterative free-space method is proposed for dielectric constant $\varepsilon _{r}^{\prime }$ determination of low-loss dielectric slabs from reflection-only measurements through simple calibration standards (reflect and air). It is applicable for dispersive samples and does not require thickness information. Simulations of nondisperive and dispersive samples are performed to validate our method. Dielectric constant measurements of polyethylene and polyoxymethylene samples (9–11 GHz) are carried out to examine the accuracy of our method.