Advisor(s)

Hossein Mosallaei

Contributor(s)

Anthony J. Devaney, Carey M. Rappaport

Date of Award

2010

Date Accepted

4-2010

Degree Grantor

Northeastern University

Degree Level

Ph.D.

Degree Name

Doctor of Philosophy

Department or Academic Unit

College of Engineering, Department of Electrical and Computer Engineering

Keywords

electrical engineering, antennas, arrays of spheres, dipole mode, dispersion diagram, metamaterials, plasmonic

Disciplines

Electrical and Computer Engineering

Abstract

This dissertation presents a theoretical study and numerical evaluations of design and applications of metamaterials. I begin with a brief review of the history of metamaterials and then investigate the design and applications of metamaterials. The thesis is divided into two main parts; the first part is devoted to the design and development of metamaterial where the second half is dedicated to applications of metamaterials in microwave and optical frequencies.

To achieve a metamaterial with desired figure of merit, we create appropriate electric and magnetic dipole moments and tailor them to the application of interest. To do that end, I investigate the problem of plane-wave scattering by 3D arrays of small spheres. Imposing the boundary conditions determines the required equations for obtaining dispersion diagram. A metamaterial constructed from unit-cells of two different high dielectric spheres is created provideing double negative (DNG) metamaterial. The developments of DNG metamaterials utilizing 3D array of magneto-dielectric spheres in free space, and dielectric spheres embedded in a negative μ (MNG) host, are also addressed. Further, I investigate the creation of backward-wave metamaterial in optical frequencies by using an array of dielectric spheres. It is highlighted how a meta-patterned structure constructed from dielectric nanospheres can provide electric and magnetic modes resulting in backward wave phenomenon.

This works reviews the performance of small antennas enabled by metamaterials. First, the behavior of small antennas embedded inside negative permittivity/permeability resonators is studied. It is illustrated how such a resonator can establish a small antenna element. To achieve a higher bandwidth and lower Q, we propose a novel design. In this scenario the dipole antenna is embedded inside a core-shell structure, with magnetic shell and dielectric core. In addition to the above applications, I also investigate the design and modeling of nano-antennas enabled by plasmonic particles. Here, I theoretically characterize the performance of array of plasmonic core-shells located over layered substrates. Engineered substrates are investigated to manipulate the radiation performance of nanoantennas. I established that by novel arraying of nano-particles and tailoring their multilayer substrates, one can successfully engineer the radiation patterns and beam angles.

Document Type

Dissertation

Rights Information

copyright 2010

Rights Holder

Seyedeh Shabnam Ghadarghadr Jahromi


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