An evolutionary-approach for material parameter determination in a broad frequency range

For radio frequency circuit and antenna design material characteristics over a broad frequency range have to be known. To determine the permittivity and losses of dielectric materials it is necessary to evaluate functions numerically. Up to 325 GHz gradient based algorithms do not find valid values for sure. In this paper we present a new evaluation-approach for complex-valued functions, based on evolutionary algorithms described in [1][2] which is able to find valid solutions in a broad frequency range. Our attention turns especially to a fast and robust optimization.