Study of atmospheric attenuation characteristics of terahertz wave based on line-by-line integration

摘要

Terahertz band communication promises new solution for satisfying the increasing demand for ultrahigh-speed wireless communication. Channel models capturing the unique peculiarities of the terahertz (THz) band are required for communication systems designing. Extreme high molecular absorption is a distinctive phenomenon that has to be involved in terahertz communication models. Research in this field has mainly focused on the characteristics along the horizontal propagation path. In this paper, we developed a unified molecular absorption model along the slant propagation path of the THz wave, based on the line-by-line integration method developed by Van-Vleck and Weisskopf and combining the molecular spectral line in the HITRAN database. Then, an in-depth analysis on the THz channel characteristics is carried out by the developed propagation models. The attenuation characteristics of terahertz waves with frequencies in the range of 0.1 to 1THz are analyzed by theoretical and mathematical modeling. The results show that the terahertz communication channel has a strong dependence on both the molecular composition of the medium and the transmission distance. The experimental results also indicate the strong absorption frequency points, weak absorption frequency points, and spectral windows.