Emerging millimeter-wave and sub-THz communications promises to address the bandwidth limitations faced at sub-6GHz bands. Communications at these higher frequency however requires multiple antennas to compensate for propagation loss resulting in pointed beams. Conditional on the link being established, these beams provide wide bandwidths. However, these links can be shortlived for users with high mobility necessitating energy-efficiency and low-latency direction-finding approaches. These challenges necessitate rethink of multi-antenna radio front-ends for them to not only synergistically work with the digital signal processor but also satisfy new features meeting the energy- and spectral-efficiencies. This talk will harness recent research in true-time-delay based spatial signal processors to enable fast direction finding as well as wideband data communications for mobile communication applicable to sub-6GHz and millimeter-wave frequencies. We describe true-time-delay based phased arrays capable of handling wide fractional bandwidths and enabling fast link discovery while maximizing the spectral- and energy-efficiencies. We will conclude this talk with custom developed multi-antenna testbeds for spatial signal processors with diverse spatial functions in spectrally diverse arrays.
Subhanshu Gupta received his M.S. and Ph.D. from the University of Washington. He is currently an Associate Professor of electrical engineering and computer science with Washington State University, Pullman with research interests in wideband transceivers, energy-efficient circuits and systems, and statistical hardware optimization for next-generation wireless communications and cryogenic interfaces. He is a recipient of the National Science Foundation CAREER Award in 2019, the Department of Defense DURIP award in 2020, and the Cisco Faculty Research Award in 2017. Subhanshu serves as an Associate Editor for the IEEE Transactions on Circuits and Systems – I and technical program committee of the IEEE Radio Frequency Integrated Circuits Symposium in 2022.