eng leong tan

Fundamental Quantity and Equations for Electromagnetics from Classical to Quantum – Unified Formulations, Hertzian Dipole Solutions and FDTD Methods

In this talk, new fundamental quantity and equations of field-impulse are presented for electromagnetics (EM). Unlike the potentials that are gauge-dependent and may not be physical nor causal, the field-impulse is gauge-independent, physically real, causal and measurable. Moreover, unlike the fields that are inadequate to describe quantum-EM, the field-impulse appears naturally in Schrodinger equation. Using single wave equation in terms of field-impulse can provide the complete description of all electromagnetics. It enables unified formulations for electrostatics, magnetostatics and electrodynamics. The single field-impulse can completely embed all fields and potentials attributed to static/dynamic and steady/nonsteady charge and/or current distributions. Its applications are demonstrated for Hertzian electric and magnetic dipole solutions that embed and unify all their electric and magnetic fields. The field-impulse equations facilitate the development of finite-difference time-domain (FDTD) methods for simulating all electromagnetic phenomena, even including electrostatics (recall that traditional FDTD has no charge but calls for Poisson/Laplace equation!). The field-impulse not only resolves the century-old field-potential/gauge dilemma, but also constitutes the fundamental physical quantity for electromagnetics from classical to quantum. Several mobile apps for technology-enhanced-learning of electromagnetics and circuits may also be demonstrated.

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 and workshops, 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 and MTT-S Speaker under TC-1 Field Theory and Computational EM Committee Speakers Bureau.