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Articles 1 - 13 of 13
Full-Text Articles in Engineering
Evaluation Of Manufacturing Methods For Antenna Design, Caleb Daniel Keathley
Evaluation Of Manufacturing Methods For Antenna Design, Caleb Daniel Keathley
Electronic Theses and Dissertations
This paper proposes several antennas designed to satisfy both dimension and frequency constraints of a handset. The proposed antennas are modeled and simulated in CST software. After multiple iterations, the final antenna designs are manufactured using both a milling machine and a 3D printer. The fabricated antennas are measured using a network analyzer and compared to their expected simulation results.
Evaluation Of Wireless Router Antennas And 3d-Printed Simulated Antenna Designs, Bibek Kattel
Evaluation Of Wireless Router Antennas And 3d-Printed Simulated Antenna Designs, Bibek Kattel
Electronic Theses and Dissertations
As the size of the electronics devices is decreasing the overall size of the antenna inside them is also decreasing. As the antenna size becomes smaller it is more difficult to manufacture them with the process of traditional manufacturing that uses the subtractive method to manufacture a structure. This is where additive manufacturing has an edge on traditional manufacturing. The use of this method to manufacture antennas has been discussed in this thesis. Five antennas from a wireless router are evaluated by modeling them in CST Microwave Studio and are modified so that they can be manufactured with 3D printing. …
Automation Of Data Collection From An Anechoic Chamber, Thomas S. Garner
Automation Of Data Collection From An Anechoic Chamber, Thomas S. Garner
Electronic Theses and Dissertations
This paper describes the calibration methods and the process that is used on the Ole Miss electrical engineering anechoic chamber. Furthermore the MATLAB code that operates the anechoic chamber has been updated to collect sweep data. The GUI also now includes a tab for calibration giving the user the ability to calibrate for their desired frequency range for when there is not sufficient calibration data already available.
Experimental Validation Of Metasurface Cloak For Dielectric Cylinder At Mircowave Frequencies, Corey Isaac Garner
Experimental Validation Of Metasurface Cloak For Dielectric Cylinder At Mircowave Frequencies, Corey Isaac Garner
Electronic Theses and Dissertations
No abstract provided.
Graphene Based Metamaterials For Terahertz Cloaking And Subwavelength Imaging, Seyedali Forouzmand
Graphene Based Metamaterials For Terahertz Cloaking And Subwavelength Imaging, Seyedali Forouzmand
Electronic Theses and Dissertations
Graphene is a two-dimensional carbon crystal that became one of the most controversial topics of research in the last few years. The intense interest in graphene stems from recent demonstrations of their potentially revolutionary electromagnetic applications – including negative refraction, subdiffraction imaging, and even invisibility – which have suggested a wide range of new devices for communications, sensing, and biomedicine. In addition, it has been shown that graphene is amenable to unique patterning schemes such as cutting, bending, folding, and fusion that are predicted to lead to interesting properties. A recent proposed application of graphene is in engineering the scattering …
Analysis And Design Of Low Profile Multiband Multifunctional Antenna Arrays, Walker F. Hunsicker
Analysis And Design Of Low Profile Multiband Multifunctional Antenna Arrays, Walker F. Hunsicker
Electronic Theses and Dissertations
Light-weight phased array antennas for aerospace and mobile applications require utilizing the same antenna aperture to provide multiple functions with dissimilar radiation pattern specifications (e.g., multiband operation for communications and tracking). Multi-functional antennas provide advantages over aggregate antenna clusters by reducing space requirements, and can aid in the optimal placement of all required apertures to provide adequate isolation between channels. Furthermore, the combination of antenna apertures into a comgeometry mitigates co-site installation issues by addressing interference within the integrated radiator design itself as opposed to the extensive analysis which is required to configure multiple radiators in close proximity. The combination …
A Complex-Envelope Fdtd Formulation Using Real-Valued Field-Variables, Qi Liu
A Complex-Envelope Fdtd Formulation Using Real-Valued Field-Variables, Qi Liu
Electronic Theses and Dissertations
Use of the complex-envelope (CE) representation of band-pass limited sources and their resulting fields increases the allowable time-step in finite-difference time-domain (FDTD) simulations. The complex envelope representation transforms band-pass limited fields and sources to complex-valued low-pass limited form and Maxwells equations from real-valued partial differential equations (PDEs) to complex-valued PDEs. Previous CE FDTD schemes have used complex valued difference equations in terms of complex valued field quantities to approximate these complex PDEs. This choice requires the use of complex numbers and complex operations in the computer program implementing the solution. An alternative CE FDTD scheme using only real numbers and …
Reconfigurable Microstrip Antennas With Tunable Radiation Pattern Characteristics, Ahmed Khidre
Reconfigurable Microstrip Antennas With Tunable Radiation Pattern Characteristics, Ahmed Khidre
Electronic Theses and Dissertations
Reconfigurable beam antenna systems are capable of changing their radiation characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because of many reasons among them; it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand of wireless networks. It might also help to reduce the deployment cost of wireless networks infrastructures. In this dissertation, designs for reconfigurable beam microstrip antennas with tunable radiation characteristics have been proposed. The method to achieve these designs is the reconfigurable parasitic element …
Broadband Approaches And Beam-Scanning Techniques For Reflectarray Antenna, Yilin Mao
Broadband Approaches And Beam-Scanning Techniques For Reflectarray Antenna, Yilin Mao
Electronic Theses and Dissertations
Reflectarray antennas combine the numerous advantages of reflector antennas and phased array antennas and create a hybrid high-gain antenna with a low-profile, low-mass, easy-fabrication, and diversified radiation performance. However, it still has some inherent drawbacks, such as limited bandwidth and scanning range, which are targeted in this dissertation. At first, the array theory approach for radiation analysis of reflectarray antennas is described and implemented. Numerical results are then presented and compared with reference results to confirm its reliability. As the most critical influential factor to the reflectarray bandwidth, the element bandwidth was studied at first, and the effects of element …
Graphics Processing Unit Acceleration Of Computational Electromagnetic Methods, Matthew Joseph Inman
Graphics Processing Unit Acceleration Of Computational Electromagnetic Methods, Matthew Joseph Inman
Electronic Theses and Dissertations
The use of Graphical Processing Units (GPU's) for scientific applications has been evolving and expanding for the decade. GPU's provide an alternative to the CPU in the creation and execution of the numerical codes that are often relied upon in to perform simulations in computational electromagnetics. While originally designed purely to display graphics on the users monitor, GPU's today are essentially powerful floating point co-processors that can be programmed not only to render complex graphics, but also perform the complex mathematical calculations often encountered in scientific computing. Currently the GPU's being produced often contain hundreds of separate cores able to …
Accelerating The Performance Of A Novel Meshless Method Based On Collocation With Radial Basis Functions By Employing A Graphical Processing Unit As A Parallel Coprocessor, Derek Owusu-Banson
Accelerating The Performance Of A Novel Meshless Method Based On Collocation With Radial Basis Functions By Employing A Graphical Processing Unit As A Parallel Coprocessor, Derek Owusu-Banson
Electronic Theses and Dissertations
In recent times, a variety of industries, applications and numerical methods including the meshless method have enjoyed a great deal of success by utilizing the graphical processing unit (GPU) as a parallel coprocessor. These benefits often include performance improvement over the previous implementations. Furthermore, applications running on graphics processors enjoy superior performance per dollar and performance per watt than implementations built exclusively on traditional central processing technologies. The GPU was originally designed for graphics acceleration but the modern GPU, known as the General Purpose Graphical Processing Unit (GPGPU) can be used for scientific and engineering calculations. The GPGPU consists of …
Advanced Design Methodologies And Novel Applications Of Reflectarray Antennas, Payam Nayeri
Advanced Design Methodologies And Novel Applications Of Reflectarray Antennas, Payam Nayeri
Electronic Theses and Dissertations
Reflectarray antennas combine the numerous advantages of printed antenna arrays and reflector antennas and create a hybrid high-gain antenna with a low-profile, low-mass, and diversified radiation performance. Reflectarrays are now emerging as the new generation of high-gain antennas for long-distance communications. In this dissertation, some advanced concepts demonstrating novel features of reflectarray antennas are presented. • First, various approaches for radiation analysis of reflectarray antennas are described and implemented. Numerical results are then presented for a variety of systems and the advantages, limitations, and accuracy of these approaches are discussed and compared with each other. • A broadband technique by …
Homogenization Of Structured Metasurfaces And Uniaxial Wire Medium Metamaterials For Microwave Applications, Chandra Sekhar Reddy Kaipa
Homogenization Of Structured Metasurfaces And Uniaxial Wire Medium Metamaterials For Microwave Applications, Chandra Sekhar Reddy Kaipa
Electronic Theses and Dissertations
In recent years, the study of electromagnetic wave interaction with artificial media has been the subject of intense research interest due to their extraordinary properties such as negative refraction, partial focusing, enhanced transmission, and spatial filtering, among others. Artificial media are crystals of various periodic metallic inclusions with dimensions of the order of ?/10 - ?/4. When compared to natural materials, the inclusions are, thus, not as small in terms of the wavelength, even in the optical band. Therefore, one should expect the electrodynamics of these media to be inherently non-local, characterized by strong spatial dispersion effects. The dissertation includes …