Time-domain measurement of the electromagnetic properties of materials

A time-domain measurement and data-reduction technique is presented that can yield the broad-band frequency-dependent values of a sample material´s electrical properties (complex permittivity and permeability). The method uses the material´s response to the spectral content of a fast rise-time pulse to determine the frequency dependence of the complex relative permittivity (ε_τ) and permeability (μ_r). The measurement procedure and data-reduction scheme are described, and the derived material values for a sample material are given. The advantages of this method include a potentially lower equipment cost and the avoidance of awkward calibration procedures that are inherent in frequency-domain methods. Though the material examined was nonmagnetic, the procedure is general and rigorous (for low-loss materials, low dispersion over the bandwidth) for the determination of both electrical and magnetic properties