Effect of uncertainty in electromagnetic media and its design implications
Ellaheh Barzegar defended her PhD thesis at the Department of Electrical Engineering on February 6th.
For some time, the propagation of electromagnetic waves through media has been studied and is a point of interest in electrical engineering research. In practice, the media are subject to uncertainty in terms of their properties, an aspect that cannot always be ignored. For her PhD research, Ellaheh Barzegar looked at the effect of medium uncertainties on EM waves and their consequent impact on the design process.
Two problem categories are distinguished in the thesis of Ellaheh Barzegar, namely, the forward problems and the inverse problems.
In forward problems, it is assumed that the randomness of the medium is known and the question to be addressed is ‘What is the effect of the medium randomness is on the output design features?’
In inverse problems, the assumption is that for a given input, the output is known, for example through a measurement, and in such a black box setting, the goal is to determine characteristics that describe the assumed randomness of the medium.
The goal of the Barzegar’s research is to propose approaches and their practical implementations to answer both forward and inverse problems in the context of a design process.
Barzegar’s research is based on three main pillars: stochastic models of electromagnetic systems, theoretical and numerical methods to quantify and characterize uncertainty, and design methodologies incorporating an acceptable level of randomness in design criteria.
The research shows how a simple, yet powerful model can be used in modeling complex electromagnetic systems. This approach approximates the inhomogeneous permittivity using a piecewise constant function, which leads to fast explicit solutions. Also, it shows the need for methods that account for uncertainties in the design process.
Title of PhD thesis: Effect of uncertainty in electromagnetic media and its design implications. Supervisors: Martijn van Beurden and S. van Eijndhoven.