Theory, Modelling, and Applications of Advanced Electromagnetic Materials
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A multitude of recent work predicts many novel concepts based on the availability
of non-natural materials; some prominent examples include transformation optics
(TO) and perfect lens. The interest in this eld has grown dramatically due to spec-
ulated possibility to allow for continuously varying material properties to steer the
incident wave at will, such as for the TO. The posed challenges for their realisation
include the limitations of numerical modelling and manufacturing techniques. A de-
sign scheme has been proposed, in this thesis, for composite materials: the desired
electromagnetic properties of composites can be engineered by judiciously varying
the volume fraction of the inclusion-to-host materials, by manipulating the geomet-
ric arrangement of inclusions, or by altering their dielectric contrast. The analysis of
the homogenised response of the designed materials at macro-scale requires effective
medium modelling techniques. The existing effective medium approximation tech-
niques have been discussed, and their pros and cons outlined. A homogenization
scheme has been introduced that is based on the interaction of the incident wave and
the nanoparticles at the micro-scale, which further requires efficient electromagnetic
modelling. The conventional nanoparticle modelling techniques, as well as the state
of the art, have been reviewed and a dipole-moment-based method to efficiently solve
modern nanoparticle-based electromagnetic problems has been outlined. The appli-
cability of the proposed scheme has been demonstrated by employing it to design
various EM devices. An improved permittivity extraction scheme has been proposed
for the homogenization of composites. Unlike classical homogenization schemes, the
extracted parameters, using the proposed technique, follow the relation between
the real and imaginary parts, that is, Kramers-Kronig relations. Several random
and periodic structures have been simulated for the purpose of extracting the ef-
fective electromagnetic properties and interpreting the results so as to establish a
connection between them.
Authors
Naeem, MajidCollections
- Theses [4125]