Abstract
Computational electromagnetics (CEM) research is important for producing simulation software that has 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, the speaker will give a brief introduction to the three physics of electromagnetic fields: circuit physics, wave physics, and ray physic. He will give an overview of past and recent progress in large scale computing in electromagnetics by his research group, and discuss various methods to overcome multi-scale problems. He will give a brief overview of the wave physics and its relationship to computation.
The speaker first discusses large scale computing result from his group as well as other groups in the world using the multi-level fast multipole algorithm (MLFMA). He 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 essential for solving multi-scale problems. The speaker 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.
The speaker 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. In this method, 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. He 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, the speaker 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, he 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, the speaker will discuss some high-frequency techniques when ray-physics becomes important.
About the speaker
Prof Weng Cho Chew received his PhD in Electrical Engineering from the Massachusetts Institute of Technology in 1980. He was a department manager and a program leader at Schlumberger-Doll Research before he joined the University of Illinois at Urbana-Champaign (UIUC) in 1985. He was the Director of the Center for Computational Electromagnetics and the Electromagnetics Laboratory at UIUC in 1995-2007. He served as the Dean of Engineering at The University of Hong Kong in 2007-2011 and is on a part-time appointment with HKU in summer 2012. He also served on the IEEE Adcom for Antennas and Propagation Society as well as Geoscience and Remote Sensing Society. He has been active with various journals and societies.
Prof Chew’s research interests are in the areas of wave physics and mathematics in inhomogeneous media for various sensing applications, integrated circuits, microstrip antenna applications, and fast algorithms for solving wave scattering and radiation problems. He is the originator of several fast algorithms for solving electromagnetics scattering and inverse problems. He led a research group that developed computer algorithms and codes that solved dense matrix systems with tens of millions of unknowns for the first time for integral equations of scattering. He has authored a book entitled Waves and Fields in Inhomogeneous Media, coauthored two books entitled Fast and Efficient Methods in Computational Electromagnetics, and Integral Equation Methods for Electromagnetic and Elastic Waves, authored and coauthored over 350 journal publications, over 400 conference publications and over ten book chapters.
Prof Chew is a Fellow of IEEE, OSA, IOP, Electromagnetics Academy, HKIE, and was an NSF Presidential Young Investigator (USA). He received the Schelkunoff Best Paper Award for AP Transaction, the IEEE Graduate Teaching Award, UIUC Campus Wide Teaching Award, and IBM Faculty Awards. He was a Founder Professor of the College of Engineering, and the First Y.T. Lo Endowed Chair Professor at UIUC. He has served as an IEEE Distinguished Lecturer, the Cheng Tsang Man Visiting Professor at Nanyang Technological University in Singapore. In 2002, ISI Citation elected him to the category of Most Highly Cited Authors (top 0.01%). He was elected by IEEE AP Society to receive the Chen-To Tai Distinguished Educator Award in 2008. He is currently the Editor-in-Chief of JEMWA/PIER journals, and on the board of directors of Applied Science Technology Research Institute, Hong Kong.
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