NSF Award
2402783
Wireless data traffic continues to grow at an exponential pace, demanding more and more bandwidth. Networks of the future will need to exploit frequencies above 100 gigahertz, which are much higher than what is typically employed today. These high frequencies need to propagate as narrow directional beams, rather than the wide- angle broadcasts currently used by base stations and cell towers. Using beams offers a number of important advantages, but also poses some significant challenges. One key challenge surrounds the question of how to adapt if the beam is blocked by an intervening obstruction between the transmitter and receiver, such as a person walking through the beam path. This research program explores a novel solution to this problem which relies on the generation of beams that follow a curved trajectory. Such beams can be generated in situations where the size of the transmitter is sufficiently large, with the appropriate engineering of the properties of the generated signal at all points across the emitting aperture. The use of such exotic beams in wireless communications is unprecedented, so many open questions must be explored in order to validate the feasibility. This work will open a new realm of possibilities for the implementation of local area networks operating at ultra-high frequencies. This project also includes a significant effort to broaden participation by under-represented groups, at the high school, undergraduate, and graduate levels.<br/><br/>This research lays the foundations for the use of self-accelerating beams in mobile wireless local area networks (LANs) operating in the near-field regime. Since conventional link analysis cannot be applied in the near field of a transmitter, fundamental electromagnetic calculations are used to establish heuristic models for link budgets that can be employed to estimate the performance of such links, including a characterization of the effect of receiver aperture and of the near-field to far-field transition for various types of self-accelerating beams. Two different strategies are explored to create electrically reconfigurable metasurfaces that can be used to generate and manipulate such beams, which could be integrated into a transmitting base station for agile adaptation to transient blockage events. In addition, issues facing the control plane will also be explored, including the development of strategies for link discovery using beams with curved trajectories, and the implications of the asymmetry of the channel resulting from the fact that the receiver is in the near field of the transmitter but not vice versa.<br/><br/>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.
