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Dissertation Defense

Unconventional Control of Electromagnetic Waves with Applications in Electrically Small Antennas, Nondiffracting Waves, and Metasurfaces

Nikolaos Chiotellis


Although electromagnetics is a well-established field within physics and engineering, it is also a rather dynamic one. In this thesis, unconventional methods are proposed for tackling modern challenges by manipulating the electromagnetic fields in different regions: reactive near field, radiative near field, and far field.

The first topic examines antennas for IoT nodes with extremely small form factors and low power consumption. As a result, they require small and relatively efficient antennas that can be tightly integrated within the node. A type of antenna, called a 3D loop, is developed, and is used in two compact IoT systems.

The second thrust aims at developing devices that generate Bessel beams and X waves (localized pulses) in their radiative near field. Here, two radiators are introduced, capable of generating Bessel beams with minimal deviation of their parameters over a broad bandwidth. This allows the generation of nondiffracting and nondispersive pulses (X waves) that remain highly localized within the device's radiative near field.

The final topic examined aims at analytically modeling the electromagnetic properties of patterned metallic sheets. Such sheets are the building blocks of metasurfaces: subwavelength textured surfaces with tailored electromagnetic properties. Having analytical models for the sheets significantly simplifies and expedites the design of metasurfaces.

Sponsored by

Professor Anthony Grbic