Noniterative Reference-Plane-Invariant Material Parameter Retrieval Method for Low-Loss Solid Samples Using One-Port Waveguide Measurements

A new microwave retrieval method is devised to extract complex relative permittivity
$\varepsilon _{r}$
and complex relative permeability
$\mu _{r}$
. It uses reflection-only scattering parameter measurements of direct and revised configurations of a measurement cell, involving an arbitrarily positioned sample, with matched and shorted terminations. It extracts
$\varepsilon _{r}$
and
$\mu _{r}$
of samples using closed-form expressions (noniterative). In addition, it could be adapted to retrieve an accurate
$\varepsilon _{r}$
of dielectric samples via a numerical optimization without resorting to knowing the sample thickness. Different scenarios are considered to examine its performance, such as the effects of inaccurate information of sample location in the cell, any air gap between the sample and the short termination, inaccurate knowledge of the sample thickness, and Fabry–Pérot resonance. Waveguide measurements at the
$X$
-band (8.2–12.4 GHz) and
$Ku$
-band (12.4–18.0 GHz) of shorter and longer dielectric samples were used to examine its performance in comparison with other methods.