Chen, Kejian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 156-164). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

Investigation of the Double-Y Balun for Feeding Pulsed Antennas Jaikrishna Venkatesan 232 Pages Directed by Dr. Waymond Scott, Jr. In this research, a double-y balun implemented with coplanar waveguide (CPW) and coplanar strip (CPS) was investigated for use with pulsed antennas. The balun was modeled using two commercial electromagnetic simulators: Momentum and HFSS. Using these numerical solvers, design information such as the design of CPW bridges, aspect ratio of the double-y balun, and stub lengths of the CPW and CPS open and short stubs were studied. A dipole, along with the outer conductor of a coaxial line was modeled in NEC. The model was used to study the currents along the arms and feedline of balanced and unbalanced dipoles. Normalized amplitude patterns were generated along the azimuth and elevation planes for balanced and unbalanced dipoles. These patterns were used later for comparison with measured patterns. Experimental work was conducted to measure the performance of a double-y balun designed to feed a resistively loaded V-dipole. The performance of the balun was investigated via VSWR, insertion loss, and antenna pattern measurements. Antenna pattern measurements along the azimuth plane were conducted for a 5 cm dipole fed without a balun, a 5 cm dipole fed with the double-y balun, a 5 cm dipole fed with the sleeve balun, a 12 cm dipole fed without a balun, and a 12 cm dipole fed with the double-y balun. The dipoles fed without a balun were fed directly with a 50 W coaxial line. An optical link, consisting of a laser modulator (LM) unit and a laser receiver (LR) unit, was constructed to measure the patterns along the elevation plane of the above dipoles. Resulting patterns agreed closely with patterns generated with NEC models. In addition, the patterns of a resistively loaded V-dipole were measured along the E-plane using the optical link. The measured patterns for the V-dipole were compared with numerical results obtained from literature. The experimental work conducted in this research illustrates the improvement obtained in the patterns of a dipole and a resistively loaded V-dipole with the use of the double-y balun.

Errata inserted inside back end-paper. / Bibliography: p. 243-249. / xvi, 249 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis presents a brief overview of microstrip antenna analysis and describes the connections between spectral and spatial domain periodic Green's functions in integral equation methods. A hybrid formulation is applied to a variety of problems from simple metal strip dipoles to more complicated microstrip geometries. A further development to finite array analysis is described. An improvement in the accuracy of this approximative technique is explored. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1997

Errata inserted inside back end-paper. / Bibliography: p. 243-249. / xvi, 249 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis presents a brief overview of microstrip antenna analysis and describes the connections between spectral and spatial domain periodic Green's functions in integral equation methods. A hybrid formulation is applied to a variety of problems from simple metal strip dipoles to more complicated microstrip geometries. A further development to finite array analysis is described. An improvement in the accuracy of this approximative technique is explored. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1997

Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1980 / Includes bibliographical references. / by Tarek Mohamed Habashy. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 110-113). Also available in electronic format on the Internet.