Permittivity estimation of rough dielectric surfaces by means of polarimetric bistatic measurements at millimeter wave frequencies

In this paper, we present preliminary results of the permittivity estimation of dielectric rough surfaces using fully-polarimetric bistatic measurements in specular direction at W-band frequencies. These results are the first validation of this method for very rough surfaces. Indeed, three Gaussian dielectric surfaces with a roughness of <; 0.0 mm (smooth), 0.3 mm (medium rough) and 2.0 mm (rough) have been generated and fabricated. The complex permittivity of the dielectric material has been measured as a reference value using the SwissTo12 Material Characterization Kit (MCK). Well calibrated measurements of the specular reflection at different angles have been carried out in the IEE bistatic polarimetric facility which is located in an anechoic chamber. The independence of the copolarized ratio of the specular reflection from the roughness has been validated with both measurement and numerical simulation. Finally, first results of the permittivity estimation of the rough surfaces are presented and analyzed.