Thickness Measurements below the Rayleigh Depth Resolution Limit Using Frequency-Modulated Continuous-Wave Millimeter and Terahertz Waves

The nondestructive testing of multilayered materials is increasingly applied in both scientific and industrial fields. In particular, developments in millimeter wave and terahertz technology open up novel measurement applications, which benefit from the nonionizing properties of this frequency range. One example is the noncontact inspection of layer thicknesses. Frequently used measuring and analysis methods lead to a resolution limit that is determined by the bandwidth of the setup. This thesis analyzes the reliable evaluation of thinner layer thicknesses using model-based signal processing