Huang Yong. / "May 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Huang, Xiaobo. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 108-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Dennis W. Prather, Dept. of Electrical & Computer Engineering. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 109-110).

Diss. Teknillinen korkeakoulu, 2006. / Myös verkkojulkaisuna.

Thesis (M.E.E.)--University of Delaware, 2006. / Principal faculty advisor: Dennis W. Prather, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

This dissertation presents the investigation of novel electromagnetic structure, circuit, and material for microwave engineering. There are four topics covered in this work: the study of a waveguide filter at W-band frequencies using electromagnetic crystal (EMXT) surfaces, the design of a dual-band amplifier with flexible frequency ratio, the analysis and testing of a compact 4:1 planar combiner with complex matching, and the investigation of a dielectric nanostructured material using a mixture of polymer and silver nanoparticles. First, a rectangular waveguide band-stop filter using electromagnetic crystal EMXT surfaces is presented. A waveguide is loaded on the top and/or the bottom walls with EMXT surface, which has a propagating band gap. An equivalent circuit is developed to model the filter behavior and to predict its stop band. A W-band prototype based on the proposed filter architecture is designed and tested. The experimental results show a rejection band centered at 97 GHz and a rejection level of 16 dB. Second, a dual-band amplifier is demonstrated with flexible frequency ratios. The proposed amplifier features novel dual-band Wilkinson power divider/combiner that allows large frequency ratios between the first and second bands (2.16 to 4.9) between the first and second operating frequencies. The stand-alone combiner has maximum potential combining efficiency of 95% and 75% at the first and second frequency bands, respectively. A 2.4 / 5.8 GHz prototype amplifier is tested to verify its dual-band functionality. Measured linear gains are 12.85 dB and 11.09 dB at the first and second frequency bands, respectively. Third, a “spatial” combiner inspired power combiner / divider for solid-state amplifier application is presented. The proposed “one-stage” combining is realized by a single port tapered to an oversized microstrip connecting to parallel multiport microstrip sections. Uniform amplitude/phase and complex impedance matching at the parallel multiport microstrips are simultaneously achieved by adjusting the geometry of the structure. A prototype 5 GHz 1-to-4 divider/combiner designed using ADS co-simulation is characterized. The measured combining efficiency of 82.4% is achieved at 5 GHz. Lastly, a nanostructure thin film with giant dielectric response is proposed by strategically dispersing silver nano-particles inside a Tropropylene glycol diacrylate (TRPGDA) polymer. The dielectric properties of the proposed thin film are experimentally extracted at the microwave frequencies. The measurement sample is prepared by laying a coplanar waveguide (CPW) line on the thin film that is supported by a glass substrate. Two-port S-parameter measurements on the CPW are performed. Dispersion mechanism due to internal inductance of the CPW line when calculating the effective dielectric constant is investigated. The extraction involves conformal mapping approximation that uses closed-form equations to calculate the dielectric constant and the loss tangent of each layer based on the effective dielectric constant and loss tangent of the entire structure. Alternatively, direct fitting technique using simulation to model the experiment is studied. The results of the two techniques are compared and discussed. The measured dielectric constant ranges from 30000 to 4600 from 1 to 20 GHz with a loss tangent of 0.55 to 1.75 from 1 to 20 GHz.

This thesis describes the design, construction and results of an accurate, 73 GHz, dual-polarized atmospheric propagation experiment conducted over a 1.8 km total length radar path. The millimetre-wave equipment consisted of a switched-polarization transmitter and a two-channel receiving system which included a phase-compensated crosspolar cancellation network and a novel, high-performance microstrip IF/LO diplexer. Meteorological instrumentation consisted of an improved electrostatic disdrometer, a raingauge network with high temporal and spatial resolution and a three-vector anemometer. A comprehensive experimental model was developed to predict the system crosspolar discrimination (XPD) response during a wide variety of conditions. This model was used to analyze, for what is believed to be the first time, the effects of: orthomode transducer port mismatches, the frequency response and error sensitivity of crosspolar cancellation systems and the range of possible cancelled system XPD responses during rain. This model also led to the development of a phase compensation technique used to improve the stability of the crosspolar cancellation network. The application of the experimental model resulted in far more accurate determinations of path XPD than would have been otherwise possible. The cancelled XPD results showed a reasonable correlation to horizontal wind velocities and agreed with model predictions for effective mean canting angles ranging between 0 and 6°. The frequent observation of negative differential attenuations and erratic uncancelled XPDs led to the conclusion that drops along the path often did not have consistent shapes and canting angles. This is believed to be due to extremely variable wind conditions. Copolar attenuations considerably lower and higher than expected from the standard predictions were observed. The higher attenuations are satisfactorily explained as resulting from vertical wind conditions and are correlated to the predictions from a proposed model which includes the effects of constant vertical wind velocities. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This research discusses the design, fabrication, integration, and characterization of micromachined millimeter-wave components and a signal source for THz multiplier source using the deep reactive ion etching technique. A wide range of advanced micromachined millimeter-wave components are proposed and fully validated with the measurement. These micromachined millimeter-wave passives include: the W-band straight and meander waveguides, W-band three-pole filter, waveguide hybrid and power divider, a novel CPW-to-waveguide transition and filter, and a novel cavity resonator for 60-GHz reconfigurable applications. The proposed THz multiplier source is a broadband 900-GHz silicon micromachined two-anode frequency tripler with the state-of-the-art performance. The research results enable the silicon micromachining technique to build low-loss and low-cost millimeter-wave components and THz signal sources.

Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Gee-Kung Chang; Committee Co-Chair: Jianjun Yu; Committee Member: John A. Buck; Committee Member: Joy Laskar; Committee Member: Umakishore Ramachandran; Committee Member: Ye Li