Dielectric properties of natural materials

We report a novel method for the determination of the dispersive dielectric properties of natural materials exhibiting high dielectric losses over a wide frequency range. Our method is based on a comparison between measured and calculated scattering parameters of a section of coaxial transmission line. We use a flexible, physically justified model for the behavior of the dielectric material whose parameters are estimated using a genetic algorithm (GA). Dielectric data is of great importance in a great number of applications like ground probing radar (GPR), time domain reflectrometry (TDR) for the determination of the volumetric water content and microwave based process tomography (/spl mu/PT), an emerging technology in process engineering applications.