A New Method for Dielectric Characterization in Sub-THz Frequency Range

A new method for broadband characterization of dielectrics in the sub-terahertz (sub-THz) frequency range is presented. Quasi-optical free space measurement setup is used to determine the complex reflection coefficient in a wide frequency band. This method makes it possible to characterize every dielectric by using only the measured complex reflection coefficient without accurate information about the thickness of dielectric sample. This method is useful in case of lossy and/or thick dielectric samples and is based on modern measurement equipment feasibility, with the possibility to make measurements in high number of frequency points. The mathematical model of the method is formulated. Finally, results of measurements for different dielectrics are presented. The obtained permittivity values of these dielectrics are comparable to those reported in the literature.