Microwave - to - submm wave reflection and transmission coefficients for investigation of biochemical water solutions

The investigation of the complex conductivity (or permittivity) of superconducting samples by grazing incidence microwave reflectivity measurements is a promising method to study of the samples with different thicknesses in wide temperature range (i.e. conductivity range) [1,2]. The main feature of the method is use of grazing incidence p-polarized wave in order to increase the sensitivity of the measurement, which makes possible such a kind of investigation. The sensitivity of the reflection coefficient to permittivity changes increases up to Brewster angle, which is almost 90 degrees for metals and superconductors. The method could be also useful for the investigation of complex permittivity of different liquids and biochemical solutions by measuring of reflection or\and transmission coefficient of the samples under test.