Wooram Lee

Wooram Lee is an Associate Professor of Electrical Engineering at Penn State University. He received his B.Sc. and M.S. degrees from KAIST and his Ph.D. from Cornell University. From 2012 to 2015, he worked at Broadcom on multi-Gbps transceivers, and from 2015 to 2020, he was at IBM T. J. Watson Research Center focusing on high-performance mmWave phased array circuits. Prof. Lee’s work has been recognized with the IEEE RFIC Best Student Paper Award (2023, as faculty advisor), the IEEE RFIC Best Industry Paper Award (2019), and the IEEE Radar Conference Best Paper Award (2009). Prof. Lee serves as an Associate Editor for the IEEE Transactions on Microwave Theory and Techniques, a Guest Editor for the IEEE Journal of Solid-State Circuits, and a member of the Technical Program Committee of the IEEE Radio-Frequency Integrated Circuits (RFIC) Symposium, the IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS), and the International Microwave Symposium (IMS). He received the Best Student Paper Award (as a faculty advisor in 2023), and Best Industry Paper Award (in 2019) from IEEE RFIC Symposium, 2022 Asia-Pacific Microwave Conference (APMC) Prize (as a co-recipient), the IEEE Solid-State Circuits Predoctoral Fellowship (the sole winner) for 2010-2011 and the Samsung Graduate Fellowship for 2007-2012. He received the Best Paper Award of the IEEE Radar Conference in 2009.

The rapid growth of wireless data traffic, along with emerging applications such as VR/AR/XR, holographic telepresence, and real-time digital twins, is driving the demand for communication systems beyond 5G. Meanwhile, next-generation sensing systems for autonomous driving and industrial automation require sub-degree angular resolution to detect small targets in complex environments. Meeting these requirements of ultra-high data rates communications and ultra-high-resolution sensing motivates operation in the sub-THz spectrum, where wide bandwidths enable high throughput and fine range resolution, and short wavelengths support dense antenna integration. However, fully exploiting the sub-THz spectrum presents significant challenges. Severe free-space path loss limits communication and sensing range, while silicon transistors offer limited gain and output power near fmax. To address these constraints, large-scale phased-array transceivers become essential. With N-element transmit and receive arrays, coherent beamforming can ideally enhance the link budget proportional to N³, compensating for path loss and device limitations while enabling multi-beam MIMO operation. A critical bottleneck in realizing scalable sub-THz beamformers lies in antenna-in-package (AiP) integration. As frequency increases, the antenna pitch (λ/2) in uniform arrays shrinks, drastically reducing the area available for RFICs and imposing severe integration, routing, and thermal constraints. This lecture presents scalable design strategies for sub-THz phased arrays, emphasizing compact, power-efficient RFIC architectures. Highlighted examples include a calibration-free passive phase shifter offering precise, low-loss control at 140 and 240 GHz, and an ultra-compact 140-GHz bidirectional transceiver front-end that minimizes chip area and switching loss while maintaining competitive output power, efficiency, and noise performance. Together, these innovations pave the way for practical, scalable sub-THz phased-array systems for future communication and sensing networks.