Complex communication and information systems operating in the Gigahertz range often combine multiple analog and digital functions. The design of such systems must capture all electromagnetic effects and interactions that impact their performance. However, it is impossible to model such systems globally at the field and device levels. Therefore, designers must take a hierarchical approach (top-down design) by which the system is conceived at a high level of abstraction and in behavioral terms. The specifications for its functional components are formulated at the network or circuit level. They, in turn, define a physical structure that requires frequency- or time-domain electromagnetic field analysis. Once the functional components have been realized, their actual physical behavior must be analyzed or measured, including possible parasitic interactions between them, and abstracted into realistic (as opposed to initially specified) behavioral models that accurately predict their impact on overall system performance (bottom-up verification). This methodology also addresses signal integrity, packaging, interconnects, electromagnetic compatibility (EMC), and thermal issues.

The purpose of this lecture is to familiarize our membership with evolving design approaches for systems of large technological and functional complexity, and to demonstrate how microwave modeling and design practices can be integrated into a wider flexible multi-level modeling environment. Techniques for interfacing models at the behavioral, network, circuit and field levels will be demonstrated. They range from order reduction of field models to the coupling of field- and circuit solvers, extraction of equivalent circuits from field solutions and measurements, behavioral representation by neural networks, and the linking of electromagnetic and thermal solvers. The key is to describe different parts of a complex structure by the most appropriate model of lowest possible order, while maintaining a two-way correspondence between functional behavior and physics across the modeling hierarchy.

Wolfgang J. R. Hoefer received the Dipl.-Ing. degree in Electrical Engineering from the Technical University Aachen, Germany, in 1965, and the D. Ing. degree from the University of Grenoble, France, in 1968.

From 1968 to 1969, he was a Lecturer at the Institut Universitaire de Technologie de Grenoble and a Research Fellow at the Institut National Polytechnique de Grenoble, France. In 1969 he joined the faculty at the Department of Electrical Engineering, the University of Ottawa, Canada, where he was a Professor until March 1992. In April 1992 he was selected to hold the NSERC Industrial Research Chair in RF Engineering at the University of Victoria, Canada. He headed the Computational Electromagnetics Research Laboratory (CERL) in the Department of Electrical and Computer Engineering in Victoria until July 2006, when he became Professor Emeritus. He held visiting appointments with the Space Division of AEG-Telefunken in Backnang, Germany, the Electromagnetics Laboratory of the Institut National Polytechnique de Grenoble, France, the Space Electronics Directorate of the Communications Research Centre in Ottawa, Canada, the University of Rome "Tor Vergata", Italy, the University of Nice - Sophia Antipolis, France, The Ferdinand Braun Institute in Berlin and the Technical University of Munich, both in Germany, the Georgia Institute of Technology, Atlanta, USA, and the University of Perugia, Italy.

Dr. Hoefer was the Chair and Co-Chair of the MTT-15 Technical Committee on Field Theory from 1990 through 2004, and Associate Editor (Electromagnetics) of the IEEE MTT Transactions from 1998 to 2000. He is the co-founder and managing editor of the International Journal of Numerical Modelling since 1988. He serves on the editorial and advisory boards of several other scientific journals and organizations. He is a Fellow of the Royal Society (the Academies of Arts, Humanities and Sciences) of Canada and a Life Fellow of the IEEE. He is a distinguished Microwave Lecturer of the MTT Society (2005 to 2007), the recipient of the 2006 Distinguished Educator Award of the IEEE MTT Society, and the President of Faustus Scientific Corporation.