Talk by Honorary Doctor of Technology 2020 Juan R. Mosig
Professor Juan R. Mosig, Ecole Polytechnique Fédérale de Lausanne, Switzerland received his Master degree from the Universidad Politécnica de Madrid, Madrid, Spain, in 1973, and the Ph.D. degree from the Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, in 1983. In 1991, he was elected Professor at the Laboratory of ElectroMagnetics and Acoustics of EPFL and he was Head of the Laboratory until 2017, when he became Emeritus EPFL Professor. His research interests include electromagnetic theory, numerical methods, and planar antennas. He has authored more than four hundred papers in international journals and four chapters in books on planar antennas&circuits. His papers received two IEEE awards in 2015 (APS Schelkunoff) and 2017 (APWL Uslenghi). Prof. Mosig has chaired two European COST Actions on Antennas (2003–2011) and he is a founding member of the European Association on Antennas and Propagation (EurAAP), whose EuCAP conference he chaired in 2006 and 2016. He is a Full Member of the Swiss Academy of Technical Sciences and a Life Fellow of IEEE.
Stratified media, Spectral Domain, Square Roots and Sommerfeld Integrals
The study of stratified media, defined as layered configurations of material substrates, is of paramount relevance in many scientific and technological areas like Acoustics, Geophysics and Lightning. In Electromagnetics, the first treatment of these problems is due to Arnold Sommerfeld who, more than one century ago, solved the most basic of all stratified media geometries, i.e. the two semi-infinite media problem. In doing so, Sommerfeld developed the fundamentals of a mathematical method, which is now known as the spectral domain approach (SDA). After many decades of latency, the analysis of stratified media using SDA knew a strong regain of interest, due to the introduction of printed technologies (microstrip and striplines) and the development in the 70s of the first planar antennas. Nowadays, SDA is used in many other areas of Electromagnetics, like Ground Penetrating Radar, satellite-based Remote Sensing and Optics&Photonics. This tutorial will review the stratified media problem and its formulation through the so-called Sommerfeld Integrals. Some tricky points, like complex square roots definitions, the relevance of a ground plane at infinity and the existence of a Sommerfeld pole (and hence of a surface wave) will be discussed. Numerical techniques will be briefly discussed and used to illustrate some recent discussions in the literature about the behavior of electromagnetic fields as a function of radial distances and of elevation angles (radiation patterns).
Time 16.6. klo 14.30-15.30
Venue: Maarintie 8, hall TU1