Materials, whether in the solid, liquid or gaseous states, may be electrically nonlinear, anisotropic, inhomogeneous and dispersive with respect to frequency. Dispersion results from loss mechanisms that differ in different types of materials and vary with temperature. Dielectric loss tangent measurements reflect the different loss mechanisms occurring in a material place in an electric field. Because of all these factors, both measurement techniques and accuracies for evaluation of dielectric properties are requisite for physical understanding. Various permittivity and dielectric loss tangent measurement techniques, including low-frequency complex impedance, free space, waveguide transmission and reflection, and resonance methods are reviewed. Measurement uncertainties are also discussed.
Journal of the American Ceramic Society
anisotropic, dielectric, dispersion, loss tangent, microwave measurements permittivity, polarization, relaxation distribution