Novel illumination and parameter extraction technique for the characterization of multilayer structures in the GHz range with deep sub-wavelength resolution

a new fast contact-free nondestructive technique (NDT) for the characterization of multilayer dielectric structures, potentially backed by a metal or water layer is proposed. By means of a novel blind analysis method of the time dependent reflected electromagnetic signal, detailed information can be obtained on the geometrical and electromagnetic parameters such as the complex valued dielectric permittivity and magnetic susceptibility of each layer of the structure. We will validate the novel technique for different materials in the 10 GHz range and compare the novel results with S-parameter measurements in the frequency domain by means of a VNA. We will discuss the impact of non-idealities on the accuracy of the retrieved parameters. Actual estimations indicate that electronic measurement systems of today allow deep sub-millimeter depth resolution, almost independently of the frequency. For a 10 GHz signal e.g. this corresponds to substantial sub-wavelength depth resolution. The novel technique has the potential for deployment in a wide range of applications ranging from the piping industry, wind energy industry, automotive, biotechnology, food industry, pharmacy and so on.