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 1528 for “"antenna"”.
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Active Antenna Bandwidth Control Using Reconfigurable Antenna Elements
Reconfigurable antennas represent a recent innovation in antenna design that changes from classical fixed-form, fixed-function antennas to modifiable structures that can be adapted to fit the requirements of a time varying system. Advances in microwave semiconductor processing technologies have …
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An innovative antenna design tool : the antenna design software
Antenna design starts with a desired electrical performance, stating the minimum gain, beamwidth and/or other parameters, across a specified bandwidth. An antenna type is chosen, and then trial-and-error is used to choose the dimensions. An initial set of dimensions is used to find the antenna's …
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NeXtRAD antenna design: X-Band dual polarised conical horn antenna
… and implementation of a dual polarised X-band antenna. The desired specifications include a centre frequency of 8.5 GHzand a 10_ azimuth-half power beam width in both vertical and horizontal polarisations. Other requirements include peak power handling of 400 W over a 50 MHz instantaneous …
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Spherical antenna array
… 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 are found …
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Antenna systems research
… is an overview of a number of investigations on antenna systems and related subjects over a period of 28 years, which has resulted in 44 publications in the technical literature, one current patent, and an M.Sc. thesis. The investigations have been grouped into 7 categories: - Log periodic …
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Antenna Pattern Synthesis
Made available in DSpace on 2014-12-04T21:02:33Z (GMT). No. of bitstreams: 1 0003133.pdf: 5113231 bytes, checksum: be923674dbf03f454f8ac79a87043c56 (MD5) Previous issue date: 1951
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FPGA controlled reconfigurable antenna
… present time, the advantages of reconfigurable antennas are numerous but limited by the method of controlling their configuration. This thesis proposes to utilize the advantages of Field Programmable Gate Arrays (FPGAs) to overcome this dilemma. Two experimental antennas are designed. The first …
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Modified Sierpinski Fractal Antenna
Fractal antennas have the potential to provide multi-band solution through the property of self similarity that the fractal shape possess. This thesis deals with some modifications of the original Sierpinski fractal patch antenna, providing additional parameters to optimize in order to get the …
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Phased Array 802.11g Antenna
… the development of a 2.4GHz phased array antenna for consumer wireless applications. 802.11g specifications include 11 channels from 2.412 GHz to 2.472 GHz. Each channel has a 22MHz minimum bandwidth with a 5 MHz center-to-center interchannel spacing. Design goals for the phased array …
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Standalone Antenna Demonstration System
Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill …
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RFID Antenna Coverage Optimization
… the problem of determining the location of RFID antennas required to read RFID tags from all items in a facility, such that the number of antennas is minimized. We formulate the problem as a Set Covering optimization problem. We develop a heuristic algorithm for this NP-Complete problem. We also …
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Selected Reflector Antenna Studies
… some of the current research topics in reflector antennas. The topics dicussed are reflector surface distortion, compensation and detection; reflector near-field analysis; and reflector antenna surface shaping. Each chapter of the thesis covers one topic and is self-contained. The most important …
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The Equiangular Spiral Antenna
Made available in DSpace on 2014-12-04T21:02:59Z (GMT). No. of bitstreams: 1 0025214.pdf: 4973193 bytes, checksum: fe846796c713e9a79934008f006ec2cc (MD5) Previous issue date: 1957
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The multiple plate antenna
Thesis: Sc. D., Massachusetts Institute of Technology, Department of Electrical Engineering, 1961.
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Multiple-frequency antenna arrays
Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering, 1964
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Wideband active antenna cancellation
There exists a simultaneous transmit and receive antenna system where the transmitted signal is creating wideband interference of the receiver. To resolve this interference problem, the isolation between the transmit antenna and the receive antenna must be increased. This thesis analyzes and …
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The spherical helical antenna
The spherical helical antenna is investigated as a new variation of the conventional helical antenna. The spherical helix is a wire antenna in a helix shape that is wound over a spherical surface instead of the standard cylindrical one. Analysis of this structure requires numerical methods and …
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The Spiro-Helical Antenna
A novel antenna made of a spiral wire wrapped into a larger helical shape is introduced. The geometry of this antenna, which is a doubly helical structure, is fully described by five independent parameters, including two radial dimensions, two pitch angles, and the number of turns. Radiation …
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Time domain antenna pattern measurements
Multipath on far-field antenna ranges causes distortion of antenna pattern measurements: The multi path components have differing path lengths and hence can be separated by illuminating the antenna under test with short-duration pulses. Alternatively, antenna measurements can be made in the …
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