Characterization of the refractive index of isotropic materials by three-detector microwave ellipsometry

A three-detector microwave ellipsometer is an experimental free-space bench for characterization of non-transparent materials. It is a non-destructive characterization technic working in oblique transmission in the frequencies range of 26 to 30 GHz. A vector network analyzer (VNA) is used as microwave source. The method is based on the determination of complex diagonal tensor which requires the measurement of the sample transmission coefficients. Calibration of the network vector analyzer is needed in order to correct the values of this coefficients due to the measurement errors. The aim of this paper is to show that One Path Two Ports calibration method is convenient for this technic.