Measurement Evaluation of Propagation Characteristics of the 300-GHz Band Focusing on the NLOS Environment

For the advanced integration of cyberspace and physical spaces in Beyond 5G (B5G) and 6G systems, technical studies are progressing to achieve an ultrahigh capacity beyond what is offered by 5G, with a focus on terahertz bands. Although the 300-GHz band is particularly promising, the utilization of the terahertz band poses significant path loss challenges, necessitating an examination of its feasibility for use in mobile access networks. On the other hand, reports on radio propagation characteristics at the 300-GHz band are scarce, and even fewer focus on addressing nonline-of-sight (NLOS) conditions. Therefore, in this paper, we provide the results of propagation experiments conducted at the 300-GHz band in both indoor and outdoor environments, including NLOS conditions. We report the obtained path loss characteristics and angle of arrival characteristics. Furthermore, on the basis of the arrival wave distribution obtained from the angle of arrival measurements, we analyze and describe the propagation mechanisms of the 300-GHz band in NLOS regions.