Speaker: James C. M. Hwang, Cornell University, Ithaca, New YorkTopic: Sub-Terahertz High-Power AmplifiersAbstract:As next-generation automobile radars, Internet of Space, and 6G wireless communications push the operation frequency above 110 GHz, high-power amplifiers (HPAs) are needed to overcome the atmospheric absorption at sub-THz frequencies. However, currently, sub-THz HPAs are limited by not only transistor technology, but also power-combining efficiency. This talk presents a novel power-combining technique with transistors distributed along a substrate-integrated waveguide (SIW). Compared to conventional microstrip or coplanar transmission lines, the SIW has much lower loss and higher power capacity without crosstalk at sub-THz frequencies. For proof of principle, a D-band (110-170 GHz) HPA with eight GaN HEMTs distributed on a SiC SIW has demonstrated a state-of-the-art power capacity of 0.2 W around 140 GHz. Much higher power, gain, and efficiency can be expected by replacing each HEMT with a multistage driver amplifier made of larger HEMTs. The novel power-combining technique is both material agnostic and technology agnostic. For example, chiplets of different technologies can be integrated on a silicon interposer containing not only a SIW power combiner, but also SIW-based high-quality duplexer and high-efficiency antenna thereby achieving a single-chip sub-THz front end. Finally, with many challenges at sub-THz frequencies, sub-THz material and device characterization will be covered if time permits.Bio:James C. M. Hwang received the B.S. degree in physics from National Taiwan University, Taipei, Taiwan, and the M.S. and Ph.D. degrees in materials science and engineering from Cornell University, Ithaca, NY, USA. He is currently a Professor with the Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA. Prior to that, he spent most of his academic career with Lehigh University, Bethlehem, PA, USA, after years of industrial experience at IBM, Yorktown Heights, NY, USA, Bell Labs, Murray Hill, NJ, USA, GE, Syracuse, NY, USA, and GAIN, Somerville, NJ, USA. He cofounded GAIN and QED, Bethlehem, PA, USA; the latter became the public company IQE and remains the world's largest compound semiconductor epitaxial wafer supplier. He was a Consultant for the U.S. Air Force Research Laboratory, Dayton, OH, USA, and a Program Officer for GHz-THz Electronics with the Air Force Office of Scientific Research, Arlington, VA, USA. He was an IEEE Distinguished Microwave Lecturer. He is an IEEE Life Fellow and an Editor of IEEE Transactions on Microwave Theory and Techniques. He has worked for decades on electronic, optoelectronic, and micro-electromechanical materials, devices, and circuits. He was the recipient of many honors and awards, including the IEEE Lester F. Eastman Award for outstanding achievement in high-performance semiconductor devices. His current research focuses on sub-terahertz materials, devices, and circuits for next-generator automobile radars, Internet of Space, and 6G wireless communications.Date & Time: March 27, 2024, 10am-11:00amCost: FreeSeminar InfoLocation: (https://engineering.utdallas.edu/engineering/files/UTD-Campus-and-Parking-Map.pdf), (https://map.utdallas.edu/), (https://www.google.com/maps/place/Erik+Jonsson+School+of+Engineering+and+Computer+Science,+ECSS/@32.9853108,-96.751746,17z/data=!4m13!1m7!3m6!1s0x864c1c7277dd89ab:0x262b391b4b52ad15!2s800+W+Campbell+Rd,+Richardson,+TX+75080!3b1!8m2!3d32.9816479!4d-96.752658!3m4!1s0x864c21fff682dc29:0x5f0c06ff030083e1!8m2!3d32.9860626!4d-96.7507344)Event Co-Sponsored by The University of Texas at Dallas and MTT-S DallasRoom: ECSS 2.102 TI Auditorium , Erik Jonsson School of Engineering and Computer Science, 800 W Campbell Rd, Richardson, Texas, United States, 75080, Virtual: https://events.vtools.ieee.org/m/409941