[IEEE AP-S Distinguished Lecturer Seminar] 1. Explicit, Implicit and Fundamental Schemes for FDTD Methods in Electromagnetics Computation and Education 2. Fundamental Quantity and Equations for Electromagnetics from Classical to Quantum
The IEEE AP-S Student Branch Chapter at the University of Toronto is pleased to invite you to a Distinguished Lecturer Seminar by Prof. Eng Leong Tan of Nanyang Technological University, Singapore. Prof. Tan is an IEEE AP-S Distinguished Lecturer (2025–2027) and a renowned expert in computational electromagnetics and EM education.
Date: Thursday, 24 July 2025
Time: 2 – 4 pm (ET)
Location: University of Toronto, Room BA B024, Bahen Centre for Information Technology, 40 St George St, Toronto, M5S 2E4
Abstract (DL talk 1: Explicit, Implicit and Fundamental Schemes for FDTD Methods in Electromagnetics Computation and Education):
In this talk, some explicit, implicit and fundamental schemes for finite-difference time-domain (FDTD) methods in electromagnetics (EM) computation and education are presented. A brief introduction is first given to the popular explicit finite-difference time-domain (FDTD) scheme, which is subjected to Courant-Friedrichs-Lewy (CFL) stability condition. This is followed by the development of various implicit FDTD schemes, which are unconditionally stable FDTD methods without the constraint of CFL time-step size. These methods include alternating direction implicit (ADI) FDTD, locally one-dimensional (LOD) FDTD, split-step (SS) FDTD, Crank-Nicolson direct splitting (CNDS), leapfrog ADI/LOD, complying-divergence implicit (CDI) FDTD, etc. They are discussed in the context of matrix exponential and classical implicit schemes named after Peaceman-Rachford, Douglas-Gunn, D’Yakonov, Strang, Crank-Nicolson, etc. It is noted that many classical and recent implicit methods can be transformed and unified under the same family of fundamental schemes. Such family of schemes feature similar update procedures with concise matrix-operator-free right-hand sides involving only vector operations. Since vector operations are much less expensive than matrix ones, the fundamental schemes are simpler and more efficient than many previous implicit FDTD methods of similar accuracy. A comparative study of various unconditionally stable FDTD methods is carried out, which includes comparisons of their update equations and efficiency gains (flops reduction) along with insights into their inter-relations. Extension of FDTD method is also presented based on new fundamental EM quantities of field-impulses that replace fields and potentials/gauge. Such method is applicable to solve all static and dynamic problems due to all charges and/or currents. Efficient implementations of fundamental schemes of FDTD methods on mobile devices are discussed for enhanced EM teaching and learning with real-time simulations anytime, anywhere.
Abstract (DL talk 2: Fundamental Quantity and Equations for Electromagnetics from Classical to Quantum – Replacing 160-Year-Old Maxwell Equations for Classical and Quantum)
It has been 160 years now since Maxwell completed his equations of electromagnetics (EM) in 1865. Today, these equations have been written in our familiar beautiful form, in terms of fields (E and B) typically and potentials (A and phi) occasionally. However, since Maxwell-Hertz-Heaviside era, there have been longstanding dilemma to use either fields or potentials (or both) for EM, and for the potentials, which gauge condition should be imposed, e.g. Lorenz gauge, Coulomb gauge, etc. The present talk will introduce new gauge-invariant physical quantity of field-impulses for new fundamental equations of electromagnetics. Unlike the potentials that are gauge-dependent and may not be physical nor causal, the field-impulses are like fields being gauge-independent, physically real, causal and measurable. Using single wave equation in terms of electric field-impulse can provide the complete description of all electromagnetics. The electric field-impulse is the single physical quantity that can unify not only electrodynamics but also electrostatics and magnetostatics, which otherwise remain independent and left separated all this while. It can completely embed all fields and potentials attributed to static/dynamic and steady/nonsteady charge and/or current distributions. The field-impulses facilitate the development of finite-difference time-domain (FDTD) method for simulating all electromagnetic phenomena, even including electrostatics (recall that traditional FDTD has no static charge which calls for Poisson/Laplace equation!). Moreover, unlike the fields that under-describe quantum-EM, the field-impulse can explain fully the Aharonov-Bohm (AB) effect and appear naturally in Schrodinger equation. The field-impulses not only resolve the century-old field-potential/gauge dilemma, but also aptly describe quantum-EM interactions. They constitute the fundamental physical quantities that are promising for replacing fields, potentials, and ultimately Maxwell equations from classical to quantum.
Biography:
Eng Leong Tan (SM’06) received the B.Eng. (Electrical) degree with first class honors from the University of Malaya, Malaysia, and the Ph.D. degree in Electrical Engineering from Nanyang Technological University (NTU), Singapore. From 1999 to 2002, he was with Institute for Infocomm Research, Singapore and since 2002, he has been with the School of Electrical & Electronic Engineering, NTU. His research interests include computational electromagnetics (CEM), multi-physics (including quantum, acoustics, thermal), RF/microwave circuit and antenna design. He has published more than 130 journal papers and presented more than 90 conference papers. He and his students received numerous paper and project awards/prizes including: 2019 Ulrich L. Rohde Innovative Conference Paper Award on Computational Techniques in Electromagnetics, First Prize in 2014 IEEE Region 10 Student Paper Contest, First Prize in 2014 IEEE MTT-S Student Design Contest on Apps for Microwave Theory and Techniques, First Prize in 2013 IEEE AP-S Antenna Design Contest, etc. He was the recipient of the IEEE AP-S Donald G. Dudley Jr. Undergraduate Teaching Award with citation: “For excellence in teaching, student mentoring, and the development of mobile technologies and computational methods for electromagnetics education.” He has been actively involved in organizing many conferences, including General Chair of PIERS 2017 Singapore, TPC Chair of ICCEM 2020, APCAP 2018 (Auckland) and 2015 (Bali), as well as TPC Chair of IEEE APS/URSI 2021. He is a Fellow of ASEAN Academy of Engineering and Technology, and a Fellow* of the Electromagnetics Academy in recognition of distinguished contributions to “Computational electromagnetics and education”. He has been appointed as the IEEE AP-S Distinguished Lecturer for 2025-2027.
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- 40 St. George Street Toronto, ON, M5S 2E4
- Toronto, Ontario
- Canada M5S 2E4
- Building: Bahen Centre for Information Technology
- Room Number: BA B024
- Starts 10 July 2025 04:00 AM UTC
- Ends 24 July 2025 07:01 PM UTC
- No Admission Charge
Speakers
Eng Leong Tan of Nanyang Technological University, Singapore
Address:Singapore