Abstract:

It has been observed that students feel confused about the different types of electromagnetic waves and are unable to realize the underlying principles and the main differences between the various modes of electromagnetic propagation. Most of the observed misconceptions regard the particular form of the wave equation (and the solution routine), the features of the propagating wave and the form and meaning of the propagation constant and the associated dispersion relation.

To enhance students’ comprehension on the various modes of electromagnetic propagation, a presentation is proposed which is made from the wave type point of view rather than focusing on specific propagation and waveguiding structures. The main aim is the various wave types and propagation modes to be presented in a comparative manner regarding, among others, the form of the wave equation and the associated solution routine, the physical meaning of the propagation constant, the form of the dispersion relation, the scope of each specific wave type, etc. The wave types to be analyzed are the Transverse Electromagnetic (TEM) waves in free space and along transmission lines, the Transverse Electric (TE) and Transverse Magnetic (TM) waves associated with metallic and dielectric waveguides and hybrid (HE/EH) waves with regard to dielectric rectangular waveguides and optical fibers. The addressed issues are, among others, the particular form of the wave equation (and its solution) for each case, the main differences between free-space and guided propagation (including the form of the dispersion relation) and the basic features of the propagating waves. More specific issues are the relation between electromagnetics and circuit theory (mainly with regard to transmission lines and metallic waveguides) the comparison between transmission lines and conventional circuits etc.

The proposed presentation is planned to take three (3) lecturing hours (in the form of an overhead seminar followed by a short test) and has been included in the current (spring 2021) semester’s “Optical Communications” course offered at the Dept. Electrical & Electronic Engineering Educators, School of Pedagogical & Technological Education (ASPETE), Athens, Greece. The aim of the presentation is the students to enhance their comprehension on the basic principles of electromagnetic propagation, realize the similarities and differences between the various wave types and develop a clearer overview of the scope and treatment of each propagation mode

Keywords:

Engineering Education, Electronic Engineering Education, Electromagnetic Waves.