Reflection coeffiicients for common indoor materials in the terahertz band

We present some preliminary measurement results for the reflection properties of common indoor materials for 300 and 1000 GHz frequencies. These material include various wooden surfaces, concrete, rubber floor surface, and glass. All the presented materials are very smooth and only have a very small amount of diffuse scattering. For smooth surfaces, the reflection coefficients can reliably be estimated based on the Fresnel equations. The presented results are a part of a larger measurement campaign aiming at searching for refractive indices for different materials. Because these indices are unknown, we find them by fitting the measured path gains to those given by the Fresnel equations. Knowing the refractive indices, researchers can model the reflection loss/coefficients simply by Fresnel equations and, e.g., adjusting the polarization based on the desired application. The reflection coefficients have applications in all scales of communications, as the reflections are usually the most probable source of multipath signal components. Modeling these non-line-of-sight (NLOS) components properly is important when modeling realistic propagation environments.