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 15 of 15 for “"Dipole Antennas"”.
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DYADIC GREEN'S FUNCTIONS FOR LAYERED GENERAL ANISOTROPIC MEDIA AND THEIR APPLICATION TO RADIATION OF DIPOLE ANTENNAS
… DGFs, the radiation problems of a Hertzian dipole and a microstrip antenna in the presence of an anisotropic substrate are solved.</p> <p>After a brief introduction, the eigenvector dyadic Green‟s functions (E-DGFs) for an unbounded general anisotropic medium through the eigen-decomposition …
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Non-foster matching of an RFID antenna
… of radio-frequency identification (RFID) tag antennas with better matching characteristics to achieve extended range for passive tags have been investigated in the ultra-high frequency (UHF) band. A variety of cavitybacked/coupled microstrip dipole antennas in 915 MHz range were considered. …
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A Dual Resonant Microstrip Antenna for UHF RFID in the Cold Chain Using Corrugated Fiberboard as a Substrate
… solution compared to conventional stripline dipole antennas widely used in commodity tags.
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Impact of ground plane serrations on radiation and impedance characteristics of a slot antenna over a conductive back plane
… are necessary qualities for RFID and wearable antennas as well as those used in many other applications. An antenna can be made indifferent to the material on which it is placed by shielding it with a conductive back plane. Slot antennas and planar dipole antennas are common choices for thin, …
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Ambient ZeroScatter: Ambient BPSK and QPSK Backscatter Communication using Existing Digital I/O Pins
… system, consisting of the BPSK ZeroScatter tag, dipole antennas, and a direct sampling digital receiver. With an input clock frequency of 2.9 Gsps, the resolution of the receiver's analog-to-digital converter (ADC) is 14 bits and the effective number of bits (ENOB) is 9 bits. By leveraging RF …
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Development and Evaluation of the Ethernet Interface(s) for the Monitoring and Control System of a New Beamforming Radio Telescope
… each consisting of 256 pairs of crossed-dipole antennas whose signals are formed into beams. The Monitoring and Control System (MCS), a subsystem of each LWA station, controls the station's subsystems and also monitors their status. This thesis addresses the interface-related features of …
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Advanced purification of aligned arrays of single-walled carbon nanotubes
… microwave irradiation of SWNT arrays. Microstrip dipole antennas of low work function metals concentrate the microwaves and selectively couple them into only metallic SWNTs (m-SWNTs). Those efforts allow for complete removal of all m-SWNTs, as revealed through systematic experimental and …
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A Prototype Platform for Array Feed Development
… by placing an array of electrically small antennas at the focal plane of a parabolic reflector. This thesis documents the design and characterization of a prototype array feed and RF receiver that were used to demonstrate the spatial filtering principle. The array consists of a 7-element …
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Antennas using left handed transmission lines
… and design of conventional wire antenna types, dipoles and loops, based on the left-handed transmission line approach. The left handed antennas have a unique feature that the wavelength of the induced current becomes shorter with decreasing frequency. The left handed transmission line concept …
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FDTD Analysis of Plasmonic and Nanojet Enhanced Photodetectors for Improved Performance
… this has been demonstrated for near- infrared dipole antennas. As an alternative to plasmonics it is proposed here that photonic nanojets may be employed to focus light onto the small active region of a photodetector. A photonic nanojet is a narrow, high-intensity electromagnetic beam that …
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Arbitrarily Oriented Biaxially Anisotropic Media: Wave Behavior and Microstrip Antennas
… in full-wave analyses of rectangular microstrip antennas printed on biaxial substrates.</p> <p>The general characteristics of electrically biaxially anisotropic (biaxial) media are presented including permittivity tensors, optic axes, orientation of the medium, and birefringence. After a detailed …
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Free-electron-driven nanoscale light sources: from Hertzian antennas to metamaterials
… be driven by free-electrons. The studied nano-antennas consisting of pair of gold nano-rods spaced by a gap resemble conventional radio dipole antennas. Nanoantennas, driven by electron beam produce emission in the visible part of the spectrum. I show that these nanoantennas are most …
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Design and analysis of reconfigurable MIMO antennas for next generation wireless communication systems
… WiFi and the existing cellular standards, the antennas in portable devices must be electrically small and are likely to be inefficient. It is also impractical to separate antennas to get low mutual coupling. As a result, the coverage of the systems would not only be limited, but the capacity of …
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Design of Miniature Low-Cost Antennas for Compact Low-Data-Rate IoT Terminals
… and energy budgets are more favorable, their antennas are often pushed into the electrically small regime, further complicating impedance matching. The aim of this thesis is to introduce a new design methodology that provides low-cost Electrically Small Antenna (ESA) solutions suitable for …