Broadband Dielectric Spectroscopy with Coaxial Transmission Line Technique - A new inversion approach

Coaxial transmission line technique is widely used to deduce broadband dielectric spectra from measured scattering parameters. The inversion algorithm in frequently used proprietary software to determine electromagnetic properties of materials remains unknown as part of a commercial closed code. Against this background, we combine a forward operator, based on transmission line theory, with a Python-based open source inversion library for having full access to the inversion procedure including e.g. parameterization, error handling and regularization. Inversion results for Teflon, ethanol and a soil sample demonstrate, that our inversion scheme performs well in comparison to the commercial Keysight materials measurement suite.