CRII: NeTS: Deployable Near-Field Sub-Terahertz Communication Systems

There has been tremendous growth in the number of wirelessly connected devices as well as at the data rates of users’ communications. Sub-terahertz (0.1 – 0.3 THz) and terahertz (0.3 THz - 10 THz) communications are envisioned as one of the promising technologies for next-generation wireless networks to meet the ever-increasing bandwidth demands. Mobile THz communications often occur in the near field of the large antennas required to overcome the propagation losses, which have very complex transmission characteristics. Further, communication systems should be resilient to the angular offsets of the devices while providing very high-speed connectivity. The goal of this project is to improve wireless link performance by addressing the challenges in THz near-field transmissions. The propagation of terahertz waves and the capacities of the links will be analyzed, and the strategies to mitigate wavefront distortions in the near field will be investigated. The solutions developed have the potential to improve the performance of THz communications and to expedite the deployment of mobile THz wireless systems. The project also involves undergraduate researchers and assists in workforce development by training future engineers to understand advanced wireless communication principles. This project will develop a framework to model and investigate wireless link capacities and mitigate wavefront distortions for mobile THz communications. It takes account of THz near-field transmission complexities such as asymmetrical up/down-link channels, inefficient beamforming, blockage, and wide bandwidth. The proposed work is divided into two intertwined thrusts: 1) study and model the wave propagation over near-field THz links by considering both transmitter and receiver configurations. A generalized near-field path loss model based on different beam types will be developed to assess downlink and uplink capacities, and the wavefronts with attractive properties in the near field such as self-healing Bessel beams will be investigated. 2) Study and mitigate phase and wavefront distortions due to wide bandwidth and angular mobility in the near-field region. Beam switching strategies will be developed. The research plan includes theoretical analysis, simulations, and experimental evaluation. The proposed techniques are expected to increase the robustness and efficiency of THz wireless links. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.