Events Calendar

EE-EP Seminar

Speaker: W. C. CHEW, University of Illinois, Urbana-Champaign, IL, USA

Talk Title: MULTI-SCALE, MULTI-PHYSICS COMPUTATIONAL ELECTROMAGNETICS

Abstract: Computational electromagnetics (CEM) research is important for producing simulation software that have been used for virtual prototyping and the design of major electrical and electronic components. Solving electromagnetics problem is a challenging task, especially when the structure is electrically large and involves multi-scale structures. This kind of structures is often encountered in circuits in electronic packaging, small antenna designs, RFID sensor designs, and antennas on complex platforms. However, more CEM is used in nano-technologies as in nano-electronics, nano-optics, and Casimir force for N/MEMS.
In this presentation, we will give a brief introduction to the three physics of electromagnetic fields: circuit physics, wave physics, and ray physic. Then we will give an overview of past and recent progress in large scale computing in electromagnetics by our research group, and discuss various methods to overcome multi-scale problems. We will give a brief overview of the wave physics and its relationship to computation. We first discuss large scale computing result from our group as well as other groups in the world using the multi-level fast multipole algorithm (MLFMA). We will discuss the use of self-box inclusion preconditioner, and parallel computing.
The development of the mixed-form fast multipole algorithm (MF-FMA) is essential to capture both circuit physics and wave physics problems. This is key for solving multi-scale problems. We will discuss the equivalence principle algorithm (EPA) to capture the multi-scale physics of complex structures. In this method, complex structures are partitioned into parts by the use of equivalence surfaces. The interaction of electromagnetic field with structures within the equivalence surface is done through scattering operators working via the equivalence currents on the equivalence surfaces. The solution within the equivalence surface can be obtained by various numerical methods. Then the interaction between equivalence surfaces is obtained via the use of translation operators. When accelerated with the mixed-form fast multipole method, large multi-scale problems can be solved in this manner.
We will also discuss the augmented electric field integral equation (A-EFIE) approach in solving the low-frequency breakdown problem as encountered in circuits in electronic packaging. The EFIE is augmented with an additional charge unknown, and an additional continuity equation relating the charge to the current. The resultant equation, after proper frequency normalization, is frequency stable down to very low frequency. This method does not suffer from the low-frequency breakdown, but it does have the low-frequency inaccuracy problem, which can be solved by perturbation method. We will also discuss the augmentation of EPA (A-EPA) to avoid low frequency breakdown, and the hybridization of EPA, A-EPA, and A-EFIE to tackle some multi-scale problems.
Next, we will discuss the use of CEM is used in nano-technologies, as in nano-electronics, nano-optics for solar cell design, and in N/MEMS for Casimir force calculation. In nano-optics, we will discuss the use of surface plasmonics, and plasmonics in nano-particles in enhancing the performace of the solar cell, as well as in spontaneous emission and Purcell effect.
To end, we will discuss some high-frequency techniques when ray-physics becomes important.


Biography: Prof. Chew is the originator of several fast algorithms for solving electromagnetics scattering and inverse problems. He has authored a widely cited book, Waves and Fields in Inhomogeneous Media, and coauthored Fast and Efficient Algorithms in Computational Electromagnetics, in addition to more than 300 scientific journal articles and 400 conference papers, several patents, and book chapters. Prof. Chew is a Fellow of IEEE and OSA. Previously, he was the director of the Center for Computational Electromagnetics and the Electromagnetics Laboratory at UIUC. Prof. Chew was the winner of the IEEE Year 2000 Graduate Teaching Award, the UIUC Campus Award for Excellence in Graduate and Professional Teaching for 2001, a Founder Professor of the College of Engineering at the University of Illinois, and the co-winner of the Schelkunoff Best Paper Award for 2001.
In 2002, ISI Citation elected him to the category of Most-Highly Cited Authors (top 0.01%). His work is cited by electromagneticists, geophysicists, mathematicians, and electro-chemists. He was the YT Lo Endowed Chair Professor of Electrical and Computer Engineering from 2005 to 2010. Before coming to University of Illinois, he was a department manager and program leader at Schlumberger-Doll Research. He was on special leave to serve as the Dean of Engineering at The University of Hong Kong from 2007 to 2011.
For more information, visit http://wcchew.ece.illinois.edu/chew/


Host: Mahta Moghaddam, EE-EP

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Marilyn Poplawski