Ultra-Broadband Material Characterization in W- and D-Band Using a Free-Space Setup

Knowledge of the complex relative permittivity of certain materials is advantageous and even required in many areas of application. These include the different fields of electrical engineering itself, but also the intersections with other disciplines such as medicine or biology. Development is moving toward higher frequency bands and bandwidths, which underlies the advantages of higher resolution in imaging, for example. This implies that the dielectric properties of investigated materials in higher frequency bands need to be known, as these can be frequency dependent. In this paper, ultra-broadband material characterization of polyvinyl chloride (PVC), polyoxymethylene (POM) and acrylonitrile butadiene styrene (ABS) samples outside of waveguide boundaries is performed using a free-space setup. The setup is fully scalable regarding the frequency range and in this work, exemplary measurements are carried out in the W-band and D-band in the frequency range from 75 GHz to 170 GHz.