Prof. Meisong Tong of Tongji University

Electromagnetic problems can be described by the integral equation approach and the integral equations can take different forms. For conducting objects, the electric field integral equation (EFIE), magnetic field integral equation (MFIE), and combined field integral equation (CFIE) can be used, while for penetrable objects, the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) equations and Müller equations can be added in addition to the EFIEs, MFIEs, and CFIEs, if the media are inhomogeneous and isotropic, and all of them are surface integral equations (SIEs). For inhomogeneous and/or anisotropic penetrable media, the volume integral equations (VIEs) are indispensable, and volume-surface integral equations (VSIEs) are also needed if such penetrable media are mixed with conducting media. All integral equations include either L operator or K operator or both as the link between the fields and sources. The L operator has a well-known low-frequency-breakdown (LFB) problem in the low-frequency analysis although the K operator does not have. To remedy the issue, the augmentation technique has been proposed in recent years, starting from the augmented EFIE (AEFIE) for conducting objects. Later on, the augmented EFIEs were also proposed for dielectric objects, but the method of moments (MoM) solutions require the use of dual basis function (DBF) since the Rao-Wilton-Glisson (RWG) basis function cannot be used to simultaneously represent both electric and magnetic current densities.

We propose hybrid field integral equations (HFIEs) for describing the EM problems with penetrable media or lossy conductors and extend to augmented HFIEs (AHFIEs) for low-frequency analysis. The HFIEs consist of the EFIE of describing the exterior of the object and the MFIE of describing its interior. Since the magnetic current density appears in the L operator in the HFIEs, we select the magnetic charge density as a new unknown function to be solved and introduce the continuity equation of magnetic current density as an extra equation, in addition to selecting the electric charge density as a new unknown function to be solved and introducing the continuity equation of electric current density as an extra equation in the traditional augmentation. The technique can be applied to the augmentation for all other integral equations including the CFIEs, PMCHWT equations, Müller equations, and VSIEs since the L operator can act on both electric and magnetic current densities. The augmented integral equations are solved by MoM where the RWG and Schaubert-Wilton-Glisson (SWG) basis functions are used to represent the surface current densities of AHFIEs and volume current densities of VIEs, respectively, while a pulse basis function is employed to represent the charge densities of AHFIEs. The complicated DBF is not needed anymore because both the electric and magnetic current densities can be represented by the RWG basis function in the SIEs and resultant system matrices can still be well-conditioned. Numerical examples are presented to illustrate the approach and good results have been obtained.

Biography:

Mei Song Tong received the B.S. and M.S. Degrees from Huazhong University of Science and Technology, Wuhan, China, respectively, and a Ph.D. degree from Arizona State University, Tempe, Arizona, USA, all in electrical engineering. He is currently the Distinguished Professor and Head of Department of Electronic Science and Technology, and Vice Dean of College of Microelectronics, Tongji University, Shanghai,

China. He has also held an adjunct professorship at the University of Illinois at Urbana-Champaign, Urbana, Illinois, USA, and an honorary professorship at the University of Hong Kong, China. He has published more than 400 papers in refereed journals and conference proceedings and co-authored six books or book chapters. His research interests include electromagnetic field theory, antenna theory and design, simulation and design of RF/microwave circuits and devices, interconnect and packaging analysis, inverse electromagnetic scattering for imaging, and computational electromagnetics.

Prof. Tong is a Fellow of the Electromagnetics Academy, a Fellow of the Japan Society for the Promotion of Science (JSPS), and a Full Member (Commission B) of the USNC/URSI. He has been the chair of the Shanghai Chapter since 2014 and the chair of the SIGHT committee in 2018, respectively, in IEEE Antennas and Propagation Society. He has served as an associate editor or guest editor for several well-known international journals, including IEEE Antennas and Propagation Magazine, IEEE Transactions on Antennas and Propagation, IEEE Transactions on Components, Packaging and Manufacturing Technology, International Journal of Numerical Modeling: Electronic Networks, Devices and Fields, Progress in Electromagnetics Research, and Journal of Electromagnetic Waves and Applications, etc. He also frequently served as a session organizer/chair, technical program committee member/chair, and general chair for some prestigious international conferences. He was the recipient of a Visiting Professorship Award from Kyoto University, Japan, in 2012, and from the University of Hong Kong, China, in 2013. He advised and coauthored ten papers that received the Best Student Paper Award from different international conferences. He was the recipient of the Travel Fellowship Award of USNC/URSI for the 31st General Assembly and Scientific Symposium (GASS) in 2014, Advance Award of Science and Technology of Shanghai Municipal Government in 2015, Fellowship Award of JSPS in 2016, Innovation Award of Universities’ Achievements of Ministry of Education of China in 2017, Innovation Achievement Award of Industry-Academia-Research Collaboration of China in 2019, and “Jinqiao” Award of Technology Market Association of China in 2020. In 2018, he was selected as the Distinguished Lecturer (DL) of IEEE Antennas and Propagation Society for 2019-2021.

Email:

Address:Department of Electronic Science and Technology Tongji University, Tongji University, Shanghai, United States