Carbon nanotubes composite materials for dipole antennas at terahertz range

This paper aims to present two types of carbon nanotubes composite materials (CNTs-composite) for antenna applications within terahertz (THz) frequency band. These composite materials consist of CNTs coated by copper and silver, separately, to construct CNTs-copper and CNTs-silver composite materials, respectively. The comparisons between the dipole antennas of these structure materials with CNTs dipole antenna and copper dipole antenna are presented to exhibit performance evaluation of the presented new dipole antennas. The mathematical modeling of CNTs-composite material is presented in this paper. The results obtained from the comparisons CNTs-copper and CNTs-silver dipole antennas are presented based on S 11 parameters, gain and efficiency

Electromagnetic modelling of bundle of single-walled carbon nanotubes with circular geometry for antenna applications

This paper aims to present an effective electromagnetic (EM) modelling approach for circular bundle of single-walled carbon nanotubes (CBSWCNTs), based on the electrical conductivity, relative complex permittivity and linear distribution impedance by applying General Ohms law for this bundle. The equivalent single conductor material (ESCM) model for personification the CB-SWCNTs is presented in this paper. The main target of this modelling approach is to estimate and investigate the EM properties of CBSWCNTs using common EM engineering tool solver CST (MWS). For this purpose, the CB-SWCNTs and ESCM dipole antennas will be designed and implemented using CST (MWS). Mathematically, the equivalent conductivity model, relative complex permittivity and other parameters of the CB-SWCNTs will be derived in this paper and considered as equivalent material parameters for the ESCM. This modelling technique is expected to provide new avenues for designing different antenna structures

Region of Interest Extraction in 3D Face Using Local Shape Descriptor

Recently, numerous efforts were focused on 3D face models due to its geometrical information and its reliability against pose estimation and identification problems. The major objective of this work is to reduce the massive amount of information contained the entire 3D face image into a distinctive and informative subset interested regions based 3D face analysis systems. The interested regions are represented by nose and eyes regions of frontal and profile 3D images. These regions are detected based on distance to local plan descriptor only which is copes well with profile views of 3D images. The statistical distribution of distance to local plane descriptor is predicted using Gaussian distribution. The framework of the proposed approach involves two modes: training mode and testing mode. In the training mode, a learning process for local shape descriptor related to the interested regions is carried out. The interested regions (nose and eyes) are extracted automatically in the testing mode. The performance evaluation of the proposed approach has been conducted using 3D images taken from GAVADB 3D face database which consists of both frontal and profile views. The proposed approach achieved high detection rate of interested regions for both frontal and profile views

Performance evaluation of dual backhaul links RF/FSO for small cells of 5G cellular system

Radio frequency (RF) backhaul links between the wireless stations especially between small cells stations such as relay stations (RSs) are insufficient with high capacities and huge number of users for 5G cellular networks. An alternative solution is using free space optics (FSO) communications, however, there are limitations in this system. In this paper we proposed a mixed of RF link together with FSO link. Using hard- selector between them and programmatically controlled according of quality of links to overcome the obstacles faced the transfer of high data. Based on the outage probability of each links an algorithm is proposed to select the optimal link and provide the power consumption with guaranteed high quality of the link. The analytical expressions for the outage probability and ergodic capacity are derived. The numerical results show the effectiveness of proposed model in terms of connectivity and capacity compared to other links

Performance assessment of the simulation modeling approach of SWCNT at THz and GHz antenna applications

This paper presents the performance evaluation for the simulation modeling approach of single-walled carbon nanotube (SWCNT) dipole antenna at THz and GHz frequency regimes. The equivalent nano-solid tube material (NSTM) modeling approach to the SWCNT is implemented into CST (MWS) software package. Where, the raw material of the NSTM model is derived from SWCNT material rather from other metal material. The comparison between NSTM modeling approach and related previous works is presented for the purpose of validation this model and investigate the behavior assessment of SWCNT dipole antenna. The results of this paper shows the good agreement between the NSTM dipole antenna and the SWCNT dipole antenna. This modeling approach will be utilized to estimate the SWCNT dipole antenna parameters, for instance, s11 parameters, radiation pattern and phase velocity. Finally, this modeling approach is presented to make possible to design and investigate different kinds of SWCNT antennas, which are significant in several area of applications