Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 137 for “"radiation pattern"”.
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Reconfigurable microstrip antennas with tunable radiation pattern characteristics
… 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 …
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Investigation of vehicle body radiation pattern as an antenna transmission system
… Apart from that, the research also studies the radiation pattern of the waves transmitted or received. Finally, the health issue is also studied and aims to meet the standard SAR requirements. The simulation software used in this study is FEMM (Finite Element Mesh Method) CAD software. FEMM is a …
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RELATIVISTIC BACKWARD WAVE OSCILLATOR WITH A GAUSSIAN RADIATION PATTERN AND RELATED TECHNOLOGIES
… high power microwave (HPM) devices with Gaussian radiation pattern are attractive for many applications. The importance of the Gaussian microwave beam is that its maximum energy density is concentrated on axis. The purpose of this study is to use a backward wave oscillator (BWO), which is …
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Design and Verification of a LabVIEW Automated Antenna Radiation Pattern Measurement System
… is a room designed to suppress electromagnetic radiation reflections so that accurate measurement of radio frequency (RF) systems such as wireless radios and antennas can take place. Despite the fact that Cal Poly already has a larger anechoic chamber, primarily used for antenna …
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Predicting Tolerance Effects on The Radiation Pattern of Reflectarray Antennas Through Interval Analysis
… focuses on predicting tolerance effects on the radiation pattern of reflectarray antennas through Interval Analysis. In fact, the uncertainty on the actual size of all parameters under fabrication tolerates such as element dimensions and dielectric properties, are modeled with interval values. …
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A synthesis procedure for array feeds to improve radiation performance of large distorted reflector antennas
… become significant and degrade the overall radiation pattern. It is for this reason that another method must be used to further improve the radiation pattern. Electromagnetic compensation for surface errors in large apace reflector antennas has been the topic of several research studies. …
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Development and Comparison of Highly Directional Loudspeakers
… sound engineers to more easily manipulate the radiation pattern of their loudspeakers to accommodate the purpose of the venue. Many commercially available products, while exhibiting good directivity at mid and high frequencies, generally lack control in the low frequency range. A new method for …
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Development of an antenna system for a relay-based wireless network
… relay station should be capable of pointing its radiation pattern to the base station antenna, thus to achieve the desired radiation pattern of the relay station, a new beam-forming module is proposed, designed and developed to generate the proper radiation pattern. The beam-forming module …
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Synthesis process using characteristic modes for multiple in situ antennas for system radiation requirements
… multiple antennas on a platform with a focus on radiation pattern performance. Characteristic mode theory is commonly used to determine how structures will radiate. Solving for the modes on a structure gives the antenna designer an idea of which modes are easily excited on a structure. Each mode …
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Analysis of Highly Coupled Wideband Antenna Arrays Using Scattering Parameter Network Models
… change the operating frequency, bandwidth, and radiation pattern from that of the single isolated element. Thus, there are some fundamental questions that remain regarding the effective operation of highly coupled arrays for beam forming, beam scanning, and aperture reconfiguration. Existing …
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Antenna design for ultra wideband radio
… the band, ensuring at least 90% total power radiation. Compatibility with an integrated circuit also requires an unobtrusive, electrically small design. The focus of this thesis is to develop an antenna for the UWB 3.1-10.6 GHz band that achieves a physically compact, planar profile, …
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UWB antenna using indium tin oxide (ITO)
… light weight, easy to feed and their attractive radiation characteristics. In this project, the performance of the UWB antenna characteristics using Indium Tin Oxide (ITO) and AgHT were investigated. Parametric studies were performed to quantify the effect of the ITO and AgHT characteristics as …
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Design, simulation, and analysis of reconfigurable antennas in GHz regime
… analysis of a reconfigurable antenna where the radiation pattern and its characteristics are altered in each operating state. Specifically three versions of the reconfigurable antenna have been designed, all made from the same materials. An industry standard simulation code is used for …
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Differentially fed active antennas
… that, the ground plane influence on antenna radiation pattern was explored and novel techniques to compensate the effects were presented. It was observed that the current flow in a coaxial cable also affects radiation pattern. Hence, a novel method was proposed to measure wireless devices in …
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Spherical antenna array
"The far field radiation pattern of an isotropic spherical antenna array with two types of element distributions, a latitude-longitude distribution and an approximately equally-spaced distribution, has been analyzed using Poisson's Sum Formula. Beamwidth expressions of both element distributions …
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Analysis and Synthesis of a New Class of Low Side Lobe Planar Arrays
… in the form of some known values of radiation pattern parameters beforehand - information that may not be available when designing arrays. A few analytical methods exist in the literature that can be used to design rectangular lattices of isotropic elements for desired half-power …
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Performance characteristics on patch antenna with sar reduction using artificial magnetic conductor (amc) for wban applications
… achieved narrow bandwidth, decrease gain, low radiation efficiency, a high specific absorption rate (SAR) value, high front-to-back ratio (FBR) and structural complexity. However, it is necessary to achieve better performance antenna for less impact of frequency detuning, by improving FBR, high …
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A Numerical Parametric Study on the Performance of a Low Profile dipole Planar Inverted Cone Antenna Placed over an Electromagnetic Bandgap Structure
… minimum at 4 GHz improved by 13.29 dB, but the pattern bandwidth decreased to 3.4:1 .The patch width, gap width, and via diameter were all varied, and It was revealed that each parameter sweep only minimally changed the impedance match and affected only the radiation pattern near the EBG …
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New Approach to finding Active Element Patterns for Large Arrays
In this study a new approach to active-element pattern analysis, for large phased array antennas, was created using Floquet's theorem. The classic approach to finding active-element patterns uses a full array simulation that can become slow and produce patterns that are specific to certain elements …
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Antennas for wireless sensor network applications
… such as impedance bandwidth, S-parameters, radiation pattern, directivity, antenna efficiency, gain and polarisation are discussed. Also discussed is the 3D electromagnetic simulation software, HFSS, which was used to simulate the antennas in this thesis. To help illustrate the use of HFSS, …
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