CAREER: Exploring Spin and Angular Momentum Waves towards Future Wireless Communication Paradigms

With increasing demand for high data-rate wireless communication systems, this project will explore new methods of radio-frequency transmission and reception using novel electromagnetic wavefronts with spin and angular momentum. These wavefronts provide a means to multiplex many different data streams at the same frequency in the air to significantly increase the data rate without increasing spectral bandwidth demand. However, practical demonstrations of such communication links in the microwave to millimeter-wave frequency band have been limited. This CAREER project explores new methods to generate and multiplex data channels using spin and angular momentum modes of electromagnetic wavefront. The research will develop enabling technologies based on electromagnetics solutions to bridge this gap through convergence of theory, design, fabrication methods, and measurement testbeds. Broadly, the proposed solutions tie into 5G wireless networks and the forthcoming 6G wireless systems. On the education part, this project will simultaneously develop industry-facing pedagogical methods, which are also inspired by the goal of increasing student engagement and integrating the research thrusts. Community outreach activities in combination with industry-academia collaborations will be pursued to support research and education goals of this project. The project will adopt a technical approach which moves away from energy-demanding signal-processing, MIMO-processing, or data-encoding techniques and introduce power-efficient passive electromagnetic guiding structures for multiplexing vortex wave modes simultaneously. Towards that goal, the project will introduce new antenna structures, underlying theory, design methods, and associated passive circuits for simultaneous generation and multiplexing of modes in free space. Specifically, the designs will enable coaxially aligned, multiplexed spin and angular momenta electromagnetic beams, which can be scaled to larger apertures and for longer distance wireless communication links. The research will also explore key features such as dynamic configuration of beam directions, focus distances, divergence angles, and suitable positioning of central-null angle to avoid link breakages. In addition, the research will bridge theory and practice by leveraging metal and dielectric 3D fabrication methods. Finaly, an experimental framework will be developed for characterization, analysis, and validation of components and for exploring novel properties of vector vortex waves. This project is jointly funded by the Communications, Circuits and Sensing Systems (CCSS) Program and the Established Program to Stimulate Competitive Research (EPSCoR). 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.