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Elliptical metasurfaces for cloaking...

Mehrpourbernety, Hossein.

Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies.
Author:	Mehrpourbernety, Hossein.
Description:	125 p.
Notes:	Source: Masters Abstracts International, Volume: 55-02.
Notes:	Adviser: Alexander B. Yakovlev.
Contained By:	Masters Abstracts International55-02(E).
Subject:	Electrical engineering.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1601181
ISBN:	9781339119144

Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies.
Mehrpourbernety, Hossein.

Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies. - 125 p.

Source: Masters Abstracts International, Volume: 55-02.

Thesis (M.S.)--The University of Mississippi, 2015.

One of the interesting applications of metamaterials is the phenomenon of electromagnetic invisibility and cloaking, which implies the suppression of bistatic scattering width of a given object, independent of incident and observation angles. In this regard, diverse techniques have been proposed to analyze and design electromagnetic cloak structures, including transformation optics, anomalous resonance methods, transmission-line networks, and plasmonic cloaking, among others. A common drawback of all these methods is that they rely on bulk materials, which are difficult to realize in practice. To overcome this issue, the mantle cloaking method has been proposed, which utilizes an ultrathin metasurface that provides anti-phase surface currents to reduce the scattering dominant mode of a given object. Recently, an analytical model has been proposed to cloak dielectric and conducting cylindrical objects realized with printed and slotted arrays at microwave frequencies. At low-terahertz (THz) frequencies, one of the promising materials to realize the required metasurface is graphene. In this regard, a graphene monolayer, characterized by inductive reactance, has been proposed to cloak dielectric planar and cylindrical objects. Then, it has been shown that a metasurface made of graphene nanopatches owns dual capacitive/inductive inductance and can be used to cloak both dielectric and conducting cylindrical objects at low-THz frequencies.

ISBN: 9781339119144Subjects--Topical Terms:

454503
Electrical engineering.

Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies.
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100 1 $a Mehrpourbernety, Hossein. $3 730273
245 1 0 $a Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies.
300 $a 125 p.
500 $a Source: Masters Abstracts International, Volume: 55-02.
500 $a Adviser: Alexander B. Yakovlev.
502 $a Thesis (M.S.)--The University of Mississippi, 2015.
520 $a One of the interesting applications of metamaterials is the phenomenon of electromagnetic invisibility and cloaking, which implies the suppression of bistatic scattering width of a given object, independent of incident and observation angles. In this regard, diverse techniques have been proposed to analyze and design electromagnetic cloak structures, including transformation optics, anomalous resonance methods, transmission-line networks, and plasmonic cloaking, among others. A common drawback of all these methods is that they rely on bulk materials, which are difficult to realize in practice. To overcome this issue, the mantle cloaking method has been proposed, which utilizes an ultrathin metasurface that provides anti-phase surface currents to reduce the scattering dominant mode of a given object. Recently, an analytical model has been proposed to cloak dielectric and conducting cylindrical objects realized with printed and slotted arrays at microwave frequencies. At low-terahertz (THz) frequencies, one of the promising materials to realize the required metasurface is graphene. In this regard, a graphene monolayer, characterized by inductive reactance, has been proposed to cloak dielectric planar and cylindrical objects. Then, it has been shown that a metasurface made of graphene nanopatches owns dual capacitive/inductive inductance and can be used to cloak both dielectric and conducting cylindrical objects at low-THz frequencies.
520 $a So far, planar and cylindrical dielectric and conducting structures have been studied. In our study, we have extended the concept and presented an accurate analytical approach to investigate the cloaking of two-dimensional (2-D) elliptical objects including infinite dielectric elliptical cylinders using graphene monolayer; metallic elliptical cylinders, and also, as a special case, 2-D metallic strips using a nanostructured graphene patch array at low-THz frequencies. We have also obtained the results for cloaking of ellipses at microwave frequencies.
520 $a In this work, we propose a novel approach to reduce the mutual coupling between two closely spaced strip dipole antennas with the elliptical metasurfaces formed by conformal printed arrays of sub-wavelength periodic elements. We show that by covering each strip with the metasurface cloak, the antennas become invisible to each other and their radiation patterns are restored as if they were isolated. The electromagnetic scattering analysis pertained to the case of antennas with the frequencies far from each other is shown to be as a good approximation of a 2-D metallic strip scattering cancellation problem solved by expressing the incident and scattered fields in terms of radial and angular Mathieu functions, with the use of sheet impedance boundary conditions at the metasurface.
520 $a In addition, we extend the novel approach based on the concept of mantle cloaking in order to reduce the mutual near-field and far-field coupling between planar antennas in printed technology. To present the idea, we consider two microstrip-fed monopole antennas resonating at slightly different frequencies and show that by cloaking the radiating part of each antenna, the antennas become invisible to each other, and thus, the mutual coupling between the antennas is suppressed drastically. The cloak structure is realized by a conformal elliptical metasurface formed by confocal printed arrays of sub-wavelength periodic elements, partially embedded in the substrate. The presence of the metasurfaces leads to the restoration of the radiation patterns of the antennas as if they were isolated.
590 $a School code: 0131.
650 4 $a Electrical engineering. $3 454503
650 4 $a Electromagnetics. $3 708560
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710 2 $a The University of Mississippi. $b Electrical Engineering. $3 708757
773 0 $t Masters Abstracts International $g 55-02(E).
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791 $a M.S.
792 $a 2015
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1601181