Cascaded Traveling Wave Amplifiers in Si/SiGe Technologies

Jim Buckwalter
UC San Diego

Monday, April 19, 2010 at 1:00PM
54-134 Engineering IV Building
Refreshments Served

Abstract: Traveling wave circuits have long been synonymous with distributed circuits where active device capacitances are absorbed into two artificial transmission lines. Consequently, distributed amplifiers offer large bandwidth but limited gain. We are investigating a new class of cascaded traveling wave circuits based on periodic regenerative feedback amplifiers. These circuits differ from conventional distributed amplifiers because amplification occurs along a single transmission line and the achievable gain is high over a limited bandwidth. Using this design approach, we have achieved Terahertz gain-bandwidth amplifiers using SiGe devices at W-band. Additionally, the regenerative traveling wave concept can equalize a broadband response and we have demonstrated a transimpedance amplifier with a 3dB bandwidth exceeding 100GHz. Traveling wave regenerative feedback also allows electronic control of reciprocal properties of transmission lines and promises alternative design approaches for millimeter-wave electronic valves.

Biography: Jim Buckwalter received the B.S. degree from Caltech, the M.S. degree from UCSB, and the Ph.D. degree from Caltech in 2006, each in electrical engineering. In July 2006, he joined the Faculty of the University of California – San Diego, where he is an Assistant Professor of electrical engineering. His research interests are traveling wave silicon integrated circuits for high-speed and high-frequency communication and energy efficient mixed-signal circuit design for high-speed transceivers. He was 'the recipient of a DAPRA Young Faculty Award in 2007.

Video: http://www.eeweb.ee.ucla.edu/videos/EE297_Unspecified_2010-04-19_01-05-AM.htm