Electromagnetic Education and Antenna Technology:
Past, Present and Future
Constantine A. Balanis
School of Electrical, Computer and Energy Engineering, Arizona State University

The field of Electromagnetics (EM) includes theoretical and applied concepts, both of which are described by a set of basic analytical laws, widely acclaimed as Maxwell’s equations.  These laws were formulated primarily through experiments conducted during the nineteenth century by many scientists, and they then were combined into a consistent set of vector equations.  These laws, both in differential and integral form, withstood the test of time for over two centuries, and they have been the foundation of electrical engineering and physics curricula.  They have successfully been applied to numerous problems, and the results have compared favorably with experimental and simulated data.  While there have been no basic changes in the initial structure of these basic laws, there has been an impressive surge in their application, especially during the last 50 or so years.  Because of the dramatic increase in the geometrical complexity of the new problems, whose geometries were not of canonical shapes and could not be described by basic orthogonal coordinate systems, the solutions of most of them could not be derived in closed-form using analytical expressions.  This necessitated the development of numerical methods to solve these complicated problems, whose solutions would otherwise have remained dormant.  The history of EM and its integration to Electrical Engineering curricula will be briefly reviewed.
The genesis of the application of numerical methods to electromagnetics may have started in the 1960s, aided and supported by the advancement of computational resources.  These computational methods and associated software have been integrated in current curricula of Electrical Engineering, both at the undergraduate and graduate levels.  While users are currently highly dependent on these computer codes, we should not lose focus on the interpretation and physical realization of the data simulated using these full-wave solvers.  Therefore, the analytical methods are, and will continue to be, the foundation of electromagnetics and provide understanding and physical interpretation of electromagnetic phenomena and interactions.
Antenna technology has undergone a dramatic evolution from the days of Hertz, with his spark-gap with end-loaded dipole, to today’s high performance Active Electronically Scanned Arrays (AESA) and multiband antennas for smart phones and mobile devices.  The antenna technology reached even greater heights with the introduction and advancements of integrated circuits, solid state technology, unique and creative radiator designs, and signal processing algorithms.  Recently electromagnetic band-gap structures, and the integration of Artificial Magnetics Conductor (AMCs), have begun to play a pivotal role.  Although numerical and computational methods, and associated full-wave simulators, have also contributed to this advancement, basic concepts and fundamental principles in the physical realization, interpretation and verification of designs of simulated should be emphasized.  The timelines over which antenna technology leaped forward are identified, and the various antenna configurations developed during those periods are highlighted.  Future trends in antenna technology are identified and suggested.
On Sunday, November 03, 2019, 14:00
Room 011, Kitot building, Tel Aviv University

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SCHOOL OF MECHANICAL ENGINEERING SEMINAR
Monday November 4, 2019 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Lagrangian Experimental Investigation of
Dispersion in Canopy Turbulence

Ron Shnapp
Ph.D student of Prof. Alex Liberzon

Transport and mixing in the atmospheric surface layer occur, in large part, due to the turbulent flow near the Earth's surface. These two processes govern the dispersal of pollutants, pesticides, pollens, dust or air-borne bacteria in the environment, and are therefore crucial in affecting the economy and our well-being. Turbulence near the surface is commonly generated when a stream of air encounters roughness obstacles on the surface, for example, man-made structures or vegetation - these flows are termed canopy flows. This work presents a novel experimental study, which focuses on the mechanisms at the heart of transport and mixing processes in the canopy flows, as described in the Lagrangian framework.
For this study, we constructed a canopy flow model within the environmental wind-tunnel laboratory, where we conducted measurements through an extended 3D Particle Tracking Velocimetry method. The results of the experiment amount to a unique data set holding millions of tracer particles' trajectories both within and above the canopy layer. Statistical analysis of the 3D trajectories revealed a locally homogeneous and locally isotropic regime of Lagrangian statistics that occurred at small scales. In the seminar, I will present the experiment itself, the locally-homogeneous regime, and statistics of the relative motion between pairs of particles so-called pair dispersion.

~~You are invited to attend a department seminar on

Thick-Film Sensors for Real-Time Monitoring of Harsh Environments
By:
Dr. Marios Sophocleous
EMPHASIS Research Centre, Department of Electrical and Computer Engineering, University of Cyprus
Abstract

Monitoring specific parameters of a system can be a major challenge when the system operates in a harsh environment. Thick-Film Technology has been proven to provide low-cost, robust and reliable sensors that can operate in such harsh environments. This talk will explain Thick-Film Technology fabrication process and how this technology can be used to develop miniaturized, multisensor arrays. The seminar will show implementations of screen-printed platinum resistance thermometers and potentiometric pH sensors based on Ruthenium (II) Oxide Ion-Selective-Electrode and a Silver/Silver Chloride Reference Electrode. Additionally, the operating principle of screen-printed dissolved oxygen sensors and resistivity/conductivity sensors will be explained whilst it will further expand to the use of such sensors for impedance spectroscopy with improved performance eliminating the classic fringing effect errors. The talk will then expand to Thick-Film Organic Electrochemical Transistors based on PEDOT:PSS with the possibility to be used for biomedical sensing applications. Finally, the talk will describe how Thick-Film sensors can be implemented in the soil, providing the missing technology for the transition to “precision agriculture” of the farming industry, whilst it will further describe applications in other harsh environments such as concrete and engine oil.

On Wednesday, October 30, 2019, 10:00
Room 011, Kitot Building