A New Calculation Method for the Dielectric Constant of Low-Loss Materials

In this paper, we present a novel technique to calculate the dielectric constant of low-loss materials with a thickness of more than half wavelength in the sample. The proposed method is valid for scenarios where the material under test (MUT) is inserted in a waveguide transmission line. The dielectric constant of the MUT is calculated by relying solely on the magnitude of the measured reflection coefficient (S11). This approach can be considered as complementary to the well-known NRW (Nicolson-Ross-Weir) method. The proposed technique provides a stable estimation of the dielectric constant of low loss materials over the studied frequency ranges. The method is also tested over a wide range of dielectric materials, where accurate estimation of their electric permittivity parameters is deduced. The proposed technique can also be extended to MUTs integrated in a transverse-electromagnetic (TEM) transmission line such as in a coaxial cable.