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Communication and Biomedical industry is in continuous growth in the last decade. Low profile small antennas are crucial in the development of commercial compact systems. Small printed antennas suffer from low efficiency. Meta material technology is used to design small printed antennas with high efficiency. Design considerations, computed and measured results of printed meta materials antennas with...
The present work investigates the feasibility of enhancing gain using two types of lenses. One is the Diffractive Optical Element (DOE) lens made of polystyrene, designed for 3GHz. The second one is a dielectric double negative (DNG) lens [2] created by a triangular lattice of holes drilled in a high dielectric permittivity material to obtain a refractive index of −1 at 3GHz. For both lenses beam...
Dielectric reflectarray antennas are studied in this paper as a possible low-loss and low-cost solution for high gain THz antennas. Variable height dielectric slabs are proposed for the reflectarray elements which allow for the use of low dielectric-constant materials for the design. A 3-D printing technology is utilized to fabricate the antenna, and both numerical and experimental results are presented...
An SAR image-based technique to obtain geometry and constitutive parameters information about low permittivity lossless dielectric materials is presented. While characterization of high permittivity dielectrics is relatively affordable in SAR images, the lower power reflected back by low permittivity objects makes their characterization a challenging task. The proposed technique combines two illumination...
A new first-principles based volume integral equation (VIE) formulation is developed for the broadband fullwave extraction of 3-D circuits, containing arbitrarily shaped lossy conductors with inhomogeneous dielectrics. It accentuates all the advantages of the VIE formulation traditionally developed for solving wave-related problems, while facilitating circuit parameter extraction such as impedance...
In extra high voltage transmission systems, the accumulation of space charges in polymeric materials have an important influence on the aging and breakdown of power equipments. It has been reported that space charges are mainly determined by trap distribution. Therefore, it is important to understand the influence of trap depths on space charges accumulation in insulating material. In this paper,...
The influence of water inside an insulating material (epoxy resin with Alumina filler) on volume resistivity, is investigated. This parameter is measured versus temperature. The water content within samples is adjusted using a climatic chamber, and monitored by weighing. Measurements show a large enhancement of volume conductivity versus water concentration and temperature. The impact of a temperature...
This paper deals with the measuring of the breakdown voltage of polymeric insulation materials stressed by high direct voltages and power-frequency high-voltages superimposed by high-frequency voltages. High-frequency highvoltage stress results in an intense heating caused by higher dielectric losses commensurate to the frequency, the permittivity and the dielectric loss factor of the materials. The...
Graphene and graphene oxide are increasingly attracting worldwide attention from academia and industry. The physical properties of graphene have been documented recently, and we have known that the sea of electrons in the two-dimensional, single layer of sp2 hybridized carbon atoms causes graphene to act both as electrical and thermal conductors. In contrast, graphene oxide, an oxidized graphene sheet...
Finite Element Analysis (FEA) has evolved over the years from a purely academic pursuit into everyday product development due to the evolution of the computation power and software developments. Engineering simulation technology allows now the detailed analyses of complex sub-systems in different configurations, combined with physical conditions that equipment faces in the real word. It is shown how...
Hybrid clusters comprising TiO2 nanoparticles (NPs) supported by discrete clusters of Au NP were fabricated through a template guided self-assembly strategy, and the electromagnetic interactions between the building blocks were investigated using experimental and theoretical tools. The performed studies reveal that electromagnetic interactions between the building blocks result in an enhancement of...
This paper concerns several epoxy resin nanocomposites. A DER 332 epoxy resin was chosen as matrix and nanosilica and/or Boron Nitride were chosen as fillers. Conduction currents results obtained using Polarization and Depolarization Current (PDC) tests at room temperature are presented and discussed. Different conduction phenomena were observed following the analysis of the variation of the current...
The physical complexity and the sensitive parameter dependence of electric conduction in polymer insulation materials make the development of high voltage direct current (HVDC) insulation devices a challenging task. Two prerequisites for a successful design process are discussed: 1) modeling and characterization of insulation materials, and 2) concepts for robust and fault tolerant insulation systems.
In this paper, dielectric spectroscopy is adapted to investigate the dielectric response, in the frequency range 10−2–106Hz, of a low-voltage cable for nuclear power plants. Cable samples were aged under accelerated stress conditions up to an equivalent aging time of 60 years. The aging procedure consisted of two phases: thermal aging by means of high temperature followed by gamma-irradiation at room...
Systems emitting High-Power Microwave Ultra-Wideband (HPM/UWB) pulses are developed for both military and civilian applications. The knowledge of the biological effects of this type of radiation is crucial for the protection of the staffs involved in the development of UWB systems but also with respect to their future applications. The French-German Research Institute of Saint-Louis has initiated...
Microwave moisture sensing provides a means to determine nondestructively the amount of water in materials. This is accomplished through the correlation of dielectric properties with moisture in the material. In this study, linear relationships between a density-independent function of the dielectric properties and moisture content of minced Vidalia onions, with slope dependent on moisture range,...
Open-ended waveguide material characterization is an effective nondestructive testing (NDT) technique for evaluating the dielectric constant and thickness of individual layers in a multilayered composite structure. A limitation of this technique is that the finite flange contributes to the estimation error, depending on the thickness and dielectric loss factor of the layers. Its effects are non-negligible...
A review of the chip-to-package interaction (CPI) results during the development and qualification of IBM's 22SOI high performance technology will be presented. Initial results and failure modes using ultra low-k (ULK) dielectric BEOL during the early development phase are shown. The fail modes include BEOL cracking under solder pads due to ULK formulations, from both planned material formulations...
Design and fabrication of dielectric lenses for terahertz (THz) focal plane arrays are presented in this paper. Lenses are designed using optical lens and ellipsoid function theory in the terahertz range (centered at f = 300GHz). In order to enhance coupling to planar circuits on wafer, two types of lenses are considered: modified hemispherical, such as extended hemispherical and hypo-hemispherical...
The w-band sapphire pillbox window had been designed in the article, with a bandwidth larger than 4GHz while VSWR less than 1.2. Structural parameters' effects on the bandwidth were analyzed and a relatively realizable assembling and welding structure was given out.
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