Estimation of permittivity of materials using sub-millimeter waves

The work presented in this article is aimed at the reconstruction of relative electric permittivity. Recent real measurements gave rise to the progress of this research. Known dielectric materials as polytetrafluorethylen (Teflon), aluminium oxide, a generic black rubber, and their combinations were examined on higher range of frequencies to get some real data and to prove or to point out possible imperfections of the prepared inverse approach. A great novelty of this research is also in using sub-millimeter waves in measurements.