Recent advances in millimeter wave (MMW) communications have ushered in a new era of high speed wireless data proliferation. Emerging 5G and 6G mobile wireless networks and low earth orbit (LEO) satellite-enabled space internet will make extensive use of the MMW bands. High performance beamforming antennas are essential to the realization of these services and are anticipated to be deployed on a massive scale (by 2030 over 2 million base-stations (BS) and small cells (SC) will be deployed in 5G-MMW infrastructure and by 2040 up to 19 million LEO SATCOM terminals will be installed with end-users). The incumbent phased array antenna (PAA) technology provides exceptional beamforming performance but, due to the high-element-count as well as poor beamformer efficiency at millimeter-waves, PAAs are costly and power-inefficient and thus do not scale well to next-generation antenna concepts like massive/giga-MIMO (1000’s of elements) and cannot meet the price point of user terminals for LEO satcom applications. In this talk I will discuss two alternative beam-scanning approaches which provide high-performance with dramatically reduced power consumption and cost: 1) Switched-beam gradient index (GRIN) lens antennas provide high aperture efficiency over extremely wide bandwidths with low-cost and power consumption. Unfortunately, they suffer from poor performance over scan angle and cannot form arbitrary beams (shape and angle). I will describe our recent efforts to address these limitations including GRIN media fabrication, lens design, and hybrid PAA/lens systems which perform like a PAA but consume much less power and can be made low-cost. 2) Low-resolution massive-MIMO arrays as well as reconfigurable intelligent surfaces (RIS) have gained significant attention over the past few years as a means of massively reducing power consumption in large-scale millimeter-wave arrays. I will describe our 1-bit millimeter-wave massive-MIMO receiver array and our new effort in a modulated transmit metasurface.

Jonathan Chisum received the Ph.D. in Electrical Engineering from the University of Colorado at Boulder in 2011. He is currently an Associate Professor of Electrical Engineering at the University of Notre Dame. From 2012 to 2015 he was a Member of Technical Staff at the Massachusetts Institute of Technology Lincoln Laboratory in the Wideband Communications and Spectrum Operations groups, where he. focused on millimeter-wave phased arrays, antennas, and transceiver design for electronic warfare applications. In 2015 he joined the faculty of the University of Notre Dame. His research interests include millimeter-wave communications and spectrum sensing using novel and engineered materials and devices to dramatically lower power consumption and cost and enable pervasive deployments. His group focuses on gradient index (GRIN) lenses for low-power millimeter-wave beam-steering antennas, nonlinear (1-bit) radio architectures for highly efficient communications and sensing up through millimeter-waves, phase-change materials for reconfigurable RF circuits for wideband distributed circuits and antennas, and microwave/spin-wave structures for low-power and chip-scale analog signal processing for spectrum sensing and protection. Dr. Chisum has published over 50 peer reviewed journal and conference papers and is a senior member of the IEEE, a member of the American Physical Society, and an elected Member of the U.S. National Committee (USNC) of the International Union or Radio Science's (URSI) Commission D (electronics and photonics). He is the current Chair for USNC URSI Commission D: Electronics and Photonics and an Associate Editor for IET Electronics Letters. He holds seven patents with five patents pending in the area of wireless circuits and antennas.