Abstract:

The throughput of antennas and antenna arrays are often limited by their electrical dimensions. The famous Harrington-Chu’s limit defines the upper bound of efficiency bandwidth products of electrically small antennas and the extension of the theory also yielded the limit of gain bandwidth products for antenna arrays. For more than half a century, these limits are considered to be invincible which defines the upper bound of the information capacity of a wireless communication system.

In this talk, those classical limits will first be recaptured and derived with the theory of radiation modes in Electrodynamics. Their impact on the capacity of wireless systems will be elaborated. It will further proceed to the recent works that demonstrated surpassing of those limits in a practical sense with time-varying operations of the antenna systems or through integration of active electronics into the radiating elements. The talk will introduce antenna architectures, semiconductor technologies and material systems that are needed to surpass these fundamental limits and push for newer limits in antenna systems.

Bio: 

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 Electrical and Computer Engineering 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 300 journal and conference papers. He has been the leading PI for multiple DARPA & IARPA programs including SPAR, M3IC, AMEBA, COFFEE and Equal-P. Dr. Wang’s research is in the general area of applied electromagnetics and microwave systems. His research often leverages on a combination of digital, time-varying concepts with state of the art material and semiconductor technology to create novel RF devices and antennas with performances beyond the conventional bounds.