Measurements on rough surface scattering in terahertz band

Results on the rough surface scattering measurements at the terahertz band (0.1 - 10 THz) are reported. The measurements were made with terahertz time domain spectroscopy (THz-TDS), providing extremely high bandwidth measurement capability with frequencies ranging from 60 GHz to around 4 THz. The measurement setup consist gold plated mirror acting as a perfect reflector and a variety of sandpapers of multiple roughnesses acting as rough surfaces. Using mirror below the sandpaper samples ensures minimum external scattering loss besides the sandpaper itself. We show the non-line-of-sight (NLoS) communications is perfectly possible in the reflected paths. Also, at short distances the diffuse scattering field theoretically allows communication. The material roughness has a clear effect on the diffuse scattering field with smooth surfaces having only a small impact on the scattering. However, the diffuse scattering field has very little energy compared with the reflected components.