The Terahertz band, spanning from 0.1~THz to 10~THz, is envisioned as a key
technology to realize ultra-high data rates in the 6G and beyond mobile
communication systems, due to its abundant bandwidth resource. However, to
realize THz communications, one substantial step is to fully understand the THz
channels, which relies on extensive channel measurements. In this paper, using
a correlation-based time domain channel sounder, measurement campaigns are
conducted in a laboratory at 140~GHz and 220~GHz. In the data post-processing
procedures, the time drift of clock signals is corrected using a linear
interpolation/extrapolation method. Based on the measured results, the main
objects that provide significant once-scattering clusters are found, based on
which the scattering losses are calculated and analyzed. Furthermore, the
channel characteristics, including path loss, shadow fading, K-factor, etc. are
calculated and compared to 3GPP standard values. The propagation analysis and
channel characteristics are helpful to study channel modeling and guide system
design for THz communications.Comment: 6 pages, 5 figures, 1 tabl