Transmittance and reflectance measurements and complex dielectric permittivity of liquid solutions in millimeter waves

This paper, for the first time, presents complex dielectric permittivity measurement of Dulbecco´s modified eagle medium based solution in the wide frequency range, from 40 to 85 GHz. Permittivity measurements of water solutions of pure salt and cane sugar have also been performed. Transmittance and reflectance spectra have been recorded by using a free-space quasi-optical millimeter-wave spectrometer, equipped with a high-power backward-wave oscillator as the source of tunable coherent radiation. The real and imaginary parts of the dielectric permittivity as functions of frequency are computed from the transmittance and reflectance spectra.