Carbon Nanotube-Composite Material for Dipole Antenna at Terahertz Range, Analysis, Properties, Efficiency and Performance

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السيد, جيلان طارق
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An-Najah National University
Carbon nanotubes (CNTs) are very interesting material for nano devices for their uncommon mechanical and electrical properties. They may be metallic or semiconducting, depending on their geometry. It has been examined for a wide range of applications including the possibility of building antennas in the nanometer scale. Many studies have been carried out to solve the problems associated with the CNTs antennas. The limitations on the adopted numerical analysis methods such as method of moments (MoM) and the inefficient assumption concerning the conductivity of CNTs materials don’t give an adequate solution. In this thesis, complex permittivity approach have been considered to define the characteristics of various terahertz antenna configurations formed by metallic CNTs materials after modeling its conductivity accurately. Complex conductivity that depends on frequency is taken into account of the CNTs material in the investigation of these advanced antennas. CNTs-composite materials have been proposed that consist of CNTs coated by a thin layer of aluminum, or copper, for THz frequency band, where the single wall carbon nanotubes (SWCNTs) is a specific structure of CNTs utilized in this work. The CNTs-composite material is a promising nano material for different applications, where CNTs are coated by other materials to modify its structure to be more effective for various applications that have been explored in recent years. The idea of using copper or aluminum in coating dipole antennas have been applied in this thesis to exhibit the enhancement of performance for the proposed dipole antennas. The radiation characteristics of various configurations of coating and non-coating CNTs dipole antenna is investigated using the concept of the effective conductivity of carbon nanotube (CNTs) material. It takes into account the frequency dependent complex permittivity of the CNTs material and gives way to a virtual CNTs dipole suitable for adaptation in conventional antenna theory and in commercial electromagnetic software solvers. Simulation results related to SWCNTs dipole antennas are presented using CST software package or HFSS to show the effect of parameters on antenna performance. HFSS (high frequency structure simulator) and CST (computer simulation technology) both simulation program have been used to simulate the same prototype. Firstly, complex permittivity as a function of frequency have been calculated by using a matlab code, then the complex conductivity of CNTs have been obtained, after that the modeling have been done to get the efficiency measurement of CNTs.