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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.
1

Design and Modeling of Planar Transformer-based Integrated Passive Devices

Wei, Tzu-Chiang 26 July 2008 (has links)
This thesis is mainly composed of two parts. The first part is to introduce the planar transformer-based circuits and their applications. The mixed-mode S parameters and the grounding effects for planar transformers are discussed. A physical model has been developed for modeling the planar transformers. In the second part, a new coil winding technique for planar transformers has been presented to realize a high-efficiency planar transformer with arbitrary turn ratio for power-split/combine and phase-shift applications. Especially, the power-split/combine architecture based on a planar transformer of cellular shape is first presented in this thesis, enabling various kinds of passive components to be widely realized using the integrated passive device processes. As an example, this thesis proposes a design procedure for high-efficiency balun component. Firstly, design a high Q transformer that considers the load impedance effects. Secondly, design the ground reference for un-balanced signal on the virtual ground symmetry axis for balanced signals. Thirdly, design impedance matching networks for minimizing un-balanced and balanced port return losses. Then, a high performance planar transformer-based balun design can be done.
2

Antenna for Integrated Passive Device

Tsai, Cheng-han 24 July 2009 (has links)
In this thesis, the study focuses on the antenna design for integrated passive devices. By using the substrate of piezoelectric material with high permittivity and introducing the fractal structures, the size reduction is obtained. Part of the research analyzes the influences of the surrounding environment on the antenna performances, including the effects of external formations, internal components, and interconnections. The results can provide the design rules for developing IPD antennas. The other part of the research emphasizes the design of IPD antenna itself, involving the investigations on the characteristics of substrate and fractals. The trade-off between compactness and radiation efficiency is pointed out, and then a design of modified ground plane is presented. When the modified design is placed on the system ground plane that exists in real system, the radiation efficiency can be improved significantly. Therefore, the concept of the compact IPD antenna is achieved.
3

Life-Cycle Cost-Based Optimal Seismic Design of Structures with Energy Dissipation Devices

Shin, Hyun 05 January 2011 (has links)
Seismic designs of building structures are currently made based on the design criterion of life-safety and this requires that the structures do not collapse to compromise safety of people in the structure, but they can be designed to experience some damage. However, this design approach has allowed large economic losses primarily due to the damage to the nonstructural components at relatively moderate levels of seismic intensities. This led to a new thinking about design approach called performance-based design approach that satisfies the life-safety objective at the same time, reduces the economic loss to an acceptable level. The performance-based design approaches are multi-level design that addresses several different levels of structural performances under different levels of seismic intensities. In this study, we have investigated the use of energy dissipating damping devices to achieve the performance of a building structure in a desirable manner over all levels of seismic intensity. Since the initial motivation of performance-based design was reducing economic loss, the life-cycle cost-based optimization is considered in this study to obtain the optimal designs with different damping devices. For the optimal design, three types of devices are used in this study: fluid viscous dampers, solid visco-elastic dampers, and yielding metallic dampers. The combinations of two different types of dampers are also examined in this study. The genetic algorithm (GA) approach is adopted as an optimizer that searches for the optimal solution in an iterative manner. Numerical results from the application of the optimal design to the selected model building are presented to demonstrate the applicability of the developed approach and to estimate the effectiveness of the obtained optimal design with each device. It is shown in the results that the optimal design with each individual damping devices or the combination of two different types of damping devices are very effective in reducing the expected failure cost as well as the displacement response quantities and fragilities. The results also show that the optimal designs focus relatively more on reducing economic losses for the lower but more frequent excitation intensities as these intensities contribute most to the failure costs. / Ph. D.
4

Design and Implementation of Miniaturized Bandpass Filters Using Integrated Passive Device and Multilayer Printed Circuit Board Process Technologies

Shih, Chih-Syuan 16 July 2011 (has links)
This thesis realizes miniature bandpass filters using integrated passive device technology. The bandpass filters are designed based on coupled resonator method with single-band and dual-band responses, using a transformer structure with high-density winging pattern. In addition, the designs adopt the electric- and magnetic-field cancellation and the feedback mechanism to produce transmission zeros in the filter responses for enhancing selectivity and stopband rejection. In order to satisfy the specific requirements of commercial bandpass filter products, this thesis designed and implemented a trisection filter with cross coupling on a low-loss RT/Duroid substrate to generate a transmission zero very near the passband.
5

Study and Design of Transformer-Based Integrated Passive Devices and Dual-Band Bandpass Filters for Wireless Applications

Huang, Chien-Hsiang 18 October 2011 (has links)
This dissertation aims to design and implement wireless passive components using domestic integrated passive device (IPD) technology. The research focuses on exploiting novel 3-D structures for various kinds of IPD-based wireless passive components including high-quality and high-efficiency planar transformers, baluns, filters, and combiners to achieve miniature size and high performance. A physical model has been developed for modeling the planar transformers. In this dissertation, a scalable transformer model in integrated passive device technology is further used to correlate with the coupled-line sections of a conventional Marchand balun. This improves the efficiency of the design of planar transformers with equivalent coupled-line parameters such as the coupling factor, and even- and odd-mode characteristic impedances and quality factors. Additionally, the proposed model-based design approach provides effective optimization techniques that incorporate geometrical and material parameters. In addition, a compact transformer-based coupled balun bandpass filter design is proposed based on integrated circuit technology and the equivalent circuit is established. Using a planar transformer with high-density fully symmetrical wiring not only greatly reduces the component size but also provides a superior stopband rejection and selectivity. Finally, by using the spiral-shaped resonators, the dual-band third-order bandpass filter has been implemented on organic substrates. The proposed BPF design is verified to overcome the elements¡¦ parasitic effects, and thus can be miniaturized and optimized with high degree of freedom. The simulation and measurement results have good agreement for the proposed design in this dissertation.
6

On-chip Spiral Inductor/transformer Design And Modeling For Rf Applications

Chen, Ji 01 January 2006 (has links)
Passive components are indispensable in the design and development of microchips for high-frequency applications. Inductors in particular are used frequently in radio frequency (RF) IC's such as low-noise amplifiers and oscillators. High performance inductor has become one of the critical components for voltage controlled oscillator (VCO) design, for its quality factor (Q) value directly affects the VCO phase noise. The optimization of inductor layout can improve its performance, but the improvement is limited by selected technology. Inductor performance is bounded by the thin routing metal and small distance from lossy substrate. On the other hand, the in-accurate inductor modeling further limits the optimization process. The on-chip inductor has been an important research topic since it was first proposed in early 1990's. Significant amount of study has been accomplished and reported in literature; whereas some methods have been used in industry, but not released to public. It is of no doubt that a comprehensive solution is not exist yet. A comprehensive study of previous will be first address. Later author will point out the in-adequacy of skin effect and proximity effect as cause of current crowding in the inductor metal. A model method embedded with new explanation of current crowding is proposed and its applicability in differential inductor and balun is validated. This study leads to a robust optimization routine to improve inductor performance without any addition technology cost and development.
7

Continuous Size-Based Separation of Microparticles in Straight Channels

Kagalwala, Taher E. 27 September 2011 (has links)
No description available.

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