Dr. Ethan Wang's SSCS DL Talk at the Integrated Systems Laboratory

Time‐Varying Electromagnetic Devices – Breaking the fundamental limit of Passives

Passive electromagnetic devices such as transmission lines, filters and antennas are essential parts of a wireless system. They often dominate the system’s efficiency, bandwidth and noise performance. Traditional passives often operate in a time-invariant manner as they are built with materials and structures that have time independent properties. They are subject to many well-known fundamental limits such as the reciprocity of transmission line, limit of quality factors of passive filters and limit of efficiency bandwidth product in electrically small antennas. Utilization of transistor based active electronics may help to overcome some of these challenges but they oftentimes incur noise and power handling issues. In this talk, I will introduce the multiple initiatives supported by NSF and DARPA on the development of a new class of electromagnetic devices that are operating in a time-varying fashion. These time-varying devices including transmission lines, filters and antennas may be constructed on semiconductor or electromechanical platforms to leverage on their time-dependent property enforced through parametric modulation or switching modes. It will be demonstrated through addition of the new time dimension several aforementioned fundamental limits of passives can be lifted. Potential new applications such a full-duplex radios, tunable RF front-ends and broadband VLF transmitters may be developed with this novel device concept.

Biography: Dr. Yuanxun Ethan Wang received his M.S. and Ph.D. degrees in electrical engineering from University of Texas at Austin, in 1996 and 1999. He became an Assistant Professor with the EE department of UCLA since Nov. 2002 and is now a Professor with the same department. Dr. Wang is an IEEE fellow and has served as an associate Editor of IEEE Transactions on Antennas and Propagation. He has published more than 200 journal and conference papers. He has been the leading PI for multiple DARPA programs including SPAR, M3IC and AMEBA. His research is in the general area of microwave systems and he often blends digital technologies and concepts into RF design, creating novel devices with performances beyond the conventional bound. Dr. Wang is the director of the Digital Microwave Lab and the Center for High Frequency Electronics in the Electrical Engineering Department of UCLA.