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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Projective solution of antenna structures assembled from arbitrarily located straight wires.

Chan, Kwok Kee. January 1973 (has links)
No description available.
122

Antenna directivity optimization using genetic algorithms /

Udina, Andrew. Unknown Date (has links)
One of the fundamental properties of an antenna is its ability to radiate or receive more energy in one given direction over all the others. This property is called the directivity. The optimization of the directivity usually requires a great deal of attention when an antenna is being designed. There are a number of iterative analytical and experimental procedures available for the optimization of the directivity, however they can be manually intensive, and very time consuming when computer simulation is employed. / Optimization of antenna parameters has been hindered by the need of techniques that prove to be reliable, robust and can search and find a global maximum. Past efforts have focused on techniques confined to small search volumes due to the time overheads of searching. With the increasing utility of the personal computer, techniques have emerged which can search large volumes efficiently and economically. Genetic Algorithms are one such technique. / Genetic Algorithms are an optimization technique based on the mechanics of natural selection, which combines the biological concepts of survival of the fittest among string structures. They operate on a population of candidate solutions and are able to change a number of parameters simultaneously while testing the solutions for goodness-of-fit. They also possess memory so that a good solution can be saved and tested from generation to generation. In this way they are able to quickly find and maintain the best solution to the problem. / A Genetic Algorithm is used to optimize the directivity of a linear array of dipole radiators. Mutual and self-coupling is taken into consideration through the use of the Method of Moments. The inter-element spacing as well as the radiator length are allowed to vary. This gives the optimization many degrees of freedom. The arrays so optimized are verified using a standard industrial antenna software simulation program. The optimized array achieves a directivity of approximately 1.5 dB better than published data for a uniform array of the same size. There is an overall reduction in the length of the array of one wavelength and the currents on the radiating elements are realisable. The final product is a basic computer aided design package capable of optimizing the directivity of a linear antenna array with the only inputs needed being the frequency of operation and the number of dipole elements. / Thesis (MEng(ElectronicsEngineering))--University of South Australia, 2005.
123

MIMO communication capacity : antenna coupling and precoding for incoherent detection /

Bikhazi, Nicolas W., January 2006 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2006. / Includes bibliographical references (p. 101-106).
124

Feasibility of incorporating a low profile di planar inverted cone antenna and a microwave amplifier in the design of a broadband E-field probe /

Yelaka, Vijayendar Reddy. January 2007 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2007. / "August 2007." Includes bibliographical references. Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2007]. 1 microfilm reel ; 35 mm.
125

Development and validation of a Method of Moments approach for modeling planar antenna structures

Kulkarni, Shashank D. January 2007 (has links)
Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: patch antennas; volume integral equation (VIE); method of moments (MoM); low order basis functions; convergence. Includes bibliographical references (leaves 169-186 ).
126

Asymptotic near-to-far-zone transformation for periodic conformal antennas embedded in canonical stuctures

Villa-Giron, Jorge M. January 2008 (has links)
Thesis (Ph.D.)--Michigan State University. Electrical and Computer Engineering, 2008. / Title from PDF t.p. (viewed on Mar. 27, 2009) Includes bibliographical references (p. 96-99). Also issued in print.
127

Ultra wide band antenna optimization /

Gracia, Christopher Anthony, January 2008 (has links)
Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 119-120)
128

On-chip and MIMO antennas for furture wireless communications /

Yan, Jie Bang. January 2008 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 96-101). Also available in electronic version.
129

Measurement of short-wavelength electrostatic fluctuations in a helicon plasma source

Hardin, Robert Aaron. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains vi, 206 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
130

A synthesis procedure for array feeds to improve radiation performance of large distorted reflector antennas /

Smith, William Travis, January 1990 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 226-230). Also available via the Internet.

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