Utilization of Bessel Beams in Wideband Sub Terahertz Communication Systems to Mitigate Beamsplit Effects in the Near-field

Exploring near-field propagation is increasingly relevant for terahertz(THz)-band communications, as very large antenna arrays (VLAA) are required to overcome the large propagation losses. In the near field, the efficiency of conventional far-field beamforming is reduced, while state-of-the-art nearfield beamfocusing requires perfect positioning and channel state information to work efficiently. In this paper, first, experimental measurements of wireless data transmission above 100 GHz in indoor scenarios are presented to highlight the need for VLAAs that will likely operate in the near field. Next, diffraction-free Bessel beams are described as a promising near-field contender, with propagation characteristics in the near field similar to those of beamforming in the far field. Numerical results and their interpretations highlight the impact of prospective wideband THz communications during system implementations. It is particularly observed that THz Bessel beams can be optimized for the given environment, potentially improving the performance characteristics of the system.