Prof Dragan Poljak from the Faculty of Engineering, University of Split visited the Lodge recently and, among other activities, presented a lecture on Fundamental Concepts in Electromagnetics.

He described how electromagnetic fields can be described by the Maxwell equations. Dragan explained how these equations were derived as a result of the contribution of different scientists and the relationship between the different variables. He then referred to the boundary conditions and what they represent in engineering practice.

Specialisation of Maxwell's equations for different cases produces the potential formula of electrostatics and magnetostatics. The simplified forms of these equations are used for Eddy currents and other applications and the stationary wave equation and many other important potential problems.

This led to the discussion of the equations used in wave propagation from an antenna to a receptor which can be solved in terms of boundary elements. Dragan also discussed the phenomena of radiation and how this can be represented using dipoles which, although simple, are appropriate for representation of antenna.

The lecture ended with Dragan explaining the behaviour of antennas used for telecommunications, particularly mobile phones. The understanding of these problems is fundamental to optimising the transmission and reducing the power needed.