Electric and magnetic characterization of materials

The knowledge of the electric and magnetic properties of materials over a broadband frequency range is an essential requirement for accurate modelling and design in several engineering applications. The interaction of incident electromagnetic fields with a material can be successfully investigated only when accurate information on the complex permittivity and magnetic permeability is attained. Regardless of the technique used for the measurement, the common challenge is the extraction of the complex relative permittivity and/or magnetic permeability from measured data by expressing the measured quantities as a function of these parameters. The inversion problem to be solved is thus affected by the mathematical model, i.e., the theoretical expressions that relate the electrical and/or magnetic parameters to the measured quantities. The inversion problem can be solved with deterministic or stochastic methods. The complex relative permittivity and magnetic permeability can be determined over the whole frequency range of interest or on a point-by-point basis (at individual frequency points).