Modeling Analysis and Research of Terahertz Wave Propagation Experiment at Sea

In this paper, the propagation loss of 0.14 THz signal propagating for 27 km at sea is measured experimentally and compared with the simulation results of model in International Telecommunication Union-Radiocommunication Sector (ITU-R). The results show that the average difference between the simulated and experimental values of signal received power is -5.2 dB, and all the simulation results overestimate the propagation loss. Considering that evaporation duct is ubiquitous in the marine atmosphere and may affect the propagation characteristics of terahertz wave, a new computational model is proposed. More than half of the simulated values based on this model agree well with the measured data, with an average difference of -1.3 dB, but the maximum difference of a single point reaches -18.6 dB, which is mainly caused by the sensitivity of the model to meteorological parameters. The "waveguide effect" in the evaporation duct environment is further simulated by adjusting the transmit antenna height from 29 m to 10 m. At this time, although the atmospheric absorption loss increases by 1 dB on average, the total path loss decreases by 5.4 dB on average, which effectively reduces the propagation loss and makes it possible for the long-range transmission of terahertz wave.