A relatively simple numerical method is introduced to separate the electric conductivity from the effective (complex) permittivity. The latter is often the outcome of measurements of the electric properties of a material. The method includes a numerical evaluation of the Kramers-Kronig transform integrals also known as Hilbert transform. Exemplarily it is applied to extract the conductivity from measured data found in the literature describing the effective permittivity of composite material.

An arbitrarily directed complex-source beam (CSB) is diffracted by an acoustically soft or hard semi-infinite circular cone. The method can be used to probe any desired part of the cone inclduing its tip. The scattered field is isolated by subtracting the incident from the diffracted field and can be used to derive diffraction coefficients for improving asymptotic methods such as the GTD or the UTD.