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Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas

Doctor of Philosophy in Communication Engineering

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Bibliographic Details
Main Author: Mohammed Taih, Gatte
Other Authors: Ping Jack, Soh, Dr.
Format: Thesis
Language:English
Published: Universiti Malaysia Perlis (UniMAP) 2017
Subjects:
Antennas (Electronics)
Wireless communication systems
Millimeter waves
Submillimeter waves
Online Access:http://dspace.unimap.edu.my:80/xmlui/handle/123456789/76631
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spelling my.unimap-766312022-10-26T01:19:01Z Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas Mohammed Taih, Gatte Ping Jack, Soh, Dr. Antennas (Electronics) Wireless communication systems Millimeter waves Submillimeter waves Doctor of Philosophy in Communication Engineering The development of millimeterwave (MMW) and Terahertz (THz) technologies for a wide range of wireless sensing and communication applications have been rapid due to the unique characteristics of waves in these bands. Antennas are regarded as the core of wireless applications, and its development for efficient operation within these bands require the use of new carbon nanomaterials such as graphene. This is due to the conductivity deterioration of conventional metals with increasing frequency. This work focuses on improving the antenna performance parameters in the MMW and THz bands based on the utilization of graphene. The employment of graphene requires mathematical modelling and characterization of its surface impedance, which are frequency dependent. The chemical potential ( c) (doping) indicated a more significant effect compared to other variables. Its values are influenced by electrical bias, magnetic bias, or chemical doping. The c = 0eV value is used as the non-doped graphene (ND-G) model, while ( c = 0.25eV and c = 0.5eV) values are used for the doped graphene (D-G) models. D-Gs were found to exhibit higher surface conductivities than ND-G, while the increasing c resulted in increased graphene conductivity. The material models of graphene (D-G and ND-G) are then integrated onto the substrate and the microwave solver software CST prior to simulations to determine the graphene based antenna (GBA) performance. These GBA antenna models indicated significant performance improvement at THz frequencies (1 THz, 1.29 THz, and 1.49 THz) compared to the copper-based antenna models. On the contrary, the use of ND-G does not always show such significant improvements at MMW frequencies (64GH), but is rather more concentrated on the bands beyond it. Two other new techniques (coating and adhesives) are proposed as alternative fabrication methods of graphene based antennas. These techniques indicated similar parameter improvements to that of the direct deposition technique in the MMW (70GHz) and THz (1.71 THz) bands. It was also discovered that antenna modeling using the adhesive technique performs better than the direct deposition technique at MMW frequencies. Next, an investigation to determine the critical frequency (CrFr) for the use of ND-G and copper at MMW and THz spectrum (30GHz-3THz) was performed. This study considers different topologies and performance parameters of ND-GBA to determine CrFr. The curves of the performance parameters are plotted against frequency to facilitate comparison between various GBA configurations. The CrFr is determined using the intersections of the performance curves for copper-based and graphene-based antenna. The investigation is also extended onto GBAs with graphene as ground or patch only. The comparison for different antenna topologies, configurations, and parameters reported different CrFrs, ranging from 0.130 - 0.240 THz, with an average of 0.147 THz. On the other hand, the critical frequencies for the patch and ground only graphene-based configurations ranged between 0.145 - 0.365 THz, with an average of 0.213 THz indicating that the CrFr of ND-GBA depends on the antenna topologies and configurations. 2017 2022-10-26T01:19:01Z 2022-10-26T01:19:01Z Thesis http://dspace.unimap.edu.my:80/xmlui/handle/123456789/76631 en Universiti Malaysia Perlis (UniMAP) Universiti Malaysia Perlis (UniMAP) School of Computer and Communication Engineering
institution Universiti Malaysia Perlis
building UniMAP Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Perlis
content_source UniMAP Library Digital Repository
url_provider http://dspace.unimap.edu.my/
language English
topic Antennas (Electronics)
Wireless communication systems
Millimeter waves
Submillimeter waves
spellingShingle Antennas (Electronics)
Wireless communication systems
Millimeter waves
Submillimeter waves
Mohammed Taih, Gatte
Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
description Doctor of Philosophy in Communication Engineering
author2 Ping Jack, Soh, Dr.
author_facet Ping Jack, Soh, Dr.
Mohammed Taih, Gatte
format Thesis
author Mohammed Taih, Gatte
author_sort Mohammed Taih, Gatte
title Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
title_short Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
title_full Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
title_fullStr Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
title_full_unstemmed Modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
title_sort modeling and characterization of graphene for efficient millimeterwave and terahertz antennas
publisher Universiti Malaysia Perlis (UniMAP)
publishDate 2017
url http://dspace.unimap.edu.my:80/xmlui/handle/123456789/76631
_version_ 1751537952655147008
score 13.214268

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