This thesis describes the investigation of photonic crystals as a substrate in microstrip phased array antennas. Alumina with a relative dielectric constant of 9.6 is used as substrate to obtain miniaturization of the components in the high-frequency range. The proposed design consists of four rectangular patches in a linear array conguration operating at 12 GHz. The antenna elements are excited by a microstrip feed line using the inset feeding technique for perfect impedance matching. A beam steering of 20o is achieved using a switched line phase shifter. Antenna parameters, including impedance matching, bandwidth, gain, directivity and the S parameters of the proposed array antenna are obtained. The simulation results are obtained with the Advanced Design System (ADS) simulator.

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.

Bibliography : leaves 219-227 / xix, 227 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1993?

Thesis (Ph. D.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2006. / Title from PDF t.p. (viewed on Nov. 17, 2008) Includes bibliographical references (p. 155-160). Also issued in print.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Dr. Jonathan Colton, Committee Chair ; Dr. John Muzzy, Committee Member ; Dr. Daniel Baldwin, Committee Member ; Dr. John Schultz, Committee Member.

Since its invention, phased array has been extensively applied in both military and civil areas. The applications include target detecting and tracking, space probe communication, broadcasting, human-machine interfaces, and remote sensing. Although the phased array applications show a broad range of potential market, there are some limitations of phased array's development: high cost, complex structure, narrow bandwidth, and high power consumption. Therefore, novel ideas are needed to reduce these constraints. In this thesis, several new approaches about the design and application of phased array are presents. First, the principle of phased array and fundamental design equations are introduced. Second, a new application of phased array antenna for radar respiration measurement is presented. By integrating a 4×4 Butler matrix with four-element antenna array, there will be four distinct main beams in radiation pattern. This new approach can improve the measurement accuracy and realize a high detecting rate. Third, a compact phased array antenna system based on dual-band operations is introduced. Dual-band function can make N-antenna system obtain 2N unique radiation beams (N is an integer) and achieve a significant size reduction compared to the conventional single-band system. To verify the design concept, a four-element phased array antenna working at 5GHz and 8GHz is designed and fabricated. The measurement results make a good agreement with the simulations. Finally, a novel architecture of steering phase feeding network by using bi-directional series-fed topology is presented. This bi-directional series-fed network needs less phase shifters and realizes steering phase function by applying control voltage.

"Theoretical modeling, design, assembly, and measurement of a novel integrated phased array radiator are presented. The droopy bowtie turnstile radiator with quad line feed meets challenging radar requirements and uses low cost manufacturing and assembly techniques. This thesis develops the complete theoretical model (antenna, balun, feeding network) of a broadband phased array radiator: the droopy bowtie turnstile radiator. A novel quad line balun feed is developed that provides a low loss, high isolation, and coincident phase-center feeding network for the droopy bowtie. The radiator and feed design combines broadband RF performance and high-isolation dual-linear polarization in a low profile, compact package that enables wide scan volume performance versus frequency. This thesis develops low-cost manufacturing and assembly techniques applied to the droopy bowtie radiator with the quad line feed. The new radiator design would utilize low cost fabrication techniques such as injection molding and 3-D printing, and also leverages automated assembly techniques. Measurement prototypes and array prototypes of droopy bowtie radiators with the quad line feed are developed for L- and X-bands. The measurements demonstrate broadband RF performance in a low profile compact package viable for wide-scale phased array applications."

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 216-221).

The computation of a piecewise smooth function that approximates a finite set of data points is decomposed into two decoupled tasks: first, the computation of the locally smooth models, and hence, the segmentation of the data into classes that consist on the sets of points best approximated by each model, and second, the computation of the normalized discriminant functions for each induced class. The approximating function is then computed as the optimal estimator with respect to this measure field. Applications to image processing and time series prediction are presented as well.