Thesis (Ph. D.)--Ohio State University, 1985. / Includes bibliographical references (leaf 308). Available online via OhioLINK's ETD Center

No description available.

No description available.

Thesis (M.S. in Engineering Science)--Naval Postgraduate School, December 2003. / Thesis advisor(s): David C. Jenn, Roberto Cristi. Includes bibliographical references (p. 95). Also available online.

No description available.

Submitted in fulfilment of the academic requirements for the Degree Master of Engineering: Electrical Engineering, Durban University of Technology. Durban. South Africa, 2015. / This dissertation describes the development and construction of the Multi-frequency Interferometer Telescope for Radio Astronomy (MITRA) at the Durban University of Technology. The MITRA station consists of 2 antenna arrays separated by a baseline distance of 8 m. Each array consists of 8 Log-Periodic Dipole Antennas (LPDAs) operating from 200 MHz to 800 MHz. The design and construction of the LPDA antenna and receiver system is described. The receiver topology provides an equivalent noise temperature of 113.1 K and 55.1 dB of gain. The Intermediate Frequency (IF) stage was designed to produce a fixed IF frequency of 800 MHz. The digital Back-End and correlator were implemented using a low cost Software Defined Radio (SDR) platform and Gnu-Radio software. Gnu-Octave was used for data analysis to generate the relevant received signal parameters including total power, real, and imaginary, magnitude and phase components. Measured results show that interference fringes were successfully detected within the bandwidth of the receiver using a Radio Frequency (RF) generator as a simulated source. This research was presented at the IEEE Africon 2013 / URSI Session Mauritius, and published in the proceedings.

No description available.

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.

A thesis submitted to the Faculty of Engineering,University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree or Doctor of Philosophy. / The aim of the thesis is to develop techniques for the analysis of antennas composed of dipoles and folded dipoles,that are efficient relative to the method-of-moments. (Abbreviation abstract) / AC2017

Thesis. 1978. Elec.E.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Elec.E.