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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.
61

Propagation characteristics of strapped coplanar waveguides

Hinz, Robert C. 28 September 1992 (has links)
The propagation characteristics of a new coupled fin line structure, with asymetrical, rectangular, top and bottom housings, is evaluated by using the modal analysis technique. The boundary Green's function of the structure, relating the surface currents to the electric fields is derived by using this technique. The propagation characteristics, i.e. propagation constant and impedances, of the structure are determined by implementing Galerkin's procedure and the results are presented for a wide range of possible structure dimensions. A CAD compatible, quasistatic analysis based on conformal mapping of the rectangular housing structure and known coplanar waveguide results is also presented. The results of the quasistatic analysis are shown to be in good agreement with the fullwave simulation at low frequencies. / Graduation date: 1993
62

Theory and Applications of Multiconductor Transmission Line Analysis for Shielded Sievenpiper and Related Structures

Elek, Francis 15 February 2011 (has links)
This thesis focuses on the analytical modeling of periodic structures which contain bands with multiple modes of propagation. The work is motivated by several structures which exhibit dual-mode propagation bands. Initially, transmission line models are focused on. Transmission line models of periodic structures have been used extensively in a wide variety of applications due to their simplicity and the ease with which one can physically interpret the resulting wave propagation effects. These models, however, are fundamentally limited, as they are only capable of capturing a single mode of propagation. In this work multiconductor transmission line theory, which is the multi-mode generalization of transmission line theory, is shown to be an effective and accurate technique for the analytical modeling of periodically loaded structures which support multiple modes of propagation. Many results from standard periodic transmission line analysis are extended and generalized in the multiconductor line analysis, providing a familiar intuitive model of the propagation phenomena. The shielded Sievenpiper structure, a periodic multilayered geometry, is analyzed in depth, and provides a canonical example of the developed analytical method. The shielded Sievenpiper structure exhibits several interesting properties which the multiconductor transmission line analysis accurately captures. It is shown that under a continuous change of geometrical parameters, the dispersion curves for the shielded structure are transformed from dual-mode to single-mode. The structure supports a stop-band characterized by complex modes, which appear as pairs of frequency varying complex conjugate propagation constants. These modes are shown to arise even though the structure is modeled as lossless. In addition to the periodic analysis, the scattering properties of finite cascades of such structures are analyzed and related to the dispersion curves generated from the periodic analysis. Excellent correspondence with full wave finite element method simulations is demonstrated. In conclusion, a physical application is presented: a compact unidirectional ring-slot antenna utilizing the shielded Sievenpiper structure is constructed and tested.
63

Nondestructive Testing of Overhead Transmission Lines: Numerical and Experimental Investigation

Kulkarni, Salil Subhash 2009 December 1900 (has links)
Overhead transmission lines are periodically inspected using both on-ground and helicopter-aided visual inspection. Factors including sun glare, cloud cover, close proximity to power lines and the rapidly changing visual circumstances make airborne inspection of power lines a particularly hazardous task. In this research, a finite element model is developed that can be used to create the theoretical dispersion curves of an overhead transmission line. The complex geometry of the overhead transmission line is the primary reason for absence of a theoretical solution to get the analytical dispersion curves. The numerical results are then verified with experimental tests using a non-contact and broadband laser detection technique. The methodology developed in this study can be further extended to a continuous monitoring system and be applied to other cable monitoring applications, such as bridge cable monitoring, which would otherwise put human inspectors at risk.
64

Research on electrical performance of differential pair design in package substrate

Huang, Chih-yi 18 July 2007 (has links)
Differential signaling is suitable for high speed signal transmission due to lower noise induction and higher common-mode noise rejection compared to its single-ended signaling counterpart. However, for a high performance differential transmission-line pair, excellent symmetry and appropriate design for substrate layer stack-up is necessary. Especially for a practical IC package substrate, differential transmission-line pair is inevitable for asymmetry because of considering the locations of IC pads and solderballs. Furthermore, different differential transmission-line pair architectures are also demanded in consideration of limited substrate floorplan space and substrate layer stack-up structures. In this thesis, several differential pairs have been implemented on the conventional 4-layer laminate package substrate. The consequent high frequency performances are measured using vector network analyzer and then compared by converting into mixed-mode S-parameters.
65

Lossy Transmission Line Modeling and Simulation Using Special Functions

Zhong, Bing January 2006 (has links)
A new algorithm for modeling and simulation of lossy interconnect structures modeled by transmission lines with Frequency Independent Line Parameters (FILP) or Frequency Dependent Line Parameters (FDLP) is developed in this research. Since frequency-dependent RLGC parameters must be employed to correctly model skin effects and dielectric losses for high-performance interconnects, we first study the behaviors of various lossy interconnects that are characterized by FILP and FDLP. Current general macromodeling methods and Model Order Reduction (MOR) algorithms are discussed. Next, some canonical integrals that are associated with transient responses of lossy transmission lines with FILP are presented. By using contour integration techniques, these integrals can be represented as closed-form expressions involving special functions, i.e., Incomplete Lipshitz-Hankel Integrals (ILHIs) and Complementary Incomplete Lipshitz-Hankel Integrals (CILHIs). Various input signals, such as ramp signals and the exponentially decaying sine signals, are used to test the expressions involving ILHIs and CILHIs. Excellent agreements are observed between the closed-form expressions involving ILHIs and CILHIs and simulation results from commercial simulation tools. We then developed a frequency-domain Dispersive Hybrid Phase-Pole Macromodel (DHPPM) for lossy transmission lines with FDLP, which consists of a constant RLGC propagation function multiplied by a residue series. The basic idea is to first extract the dominant physical phenomenology by using a propagation function in the frequency domain that is modeled by FILP. A rational function approximation is then used to account for the remaining effects of FDLP lines. By using a partial fraction expansion and analytically evaluating the required inverse Fourier transform integrals, the time-domain DHPPM can be decomposed as a sum of canonical transient responses for lines with FILP for various excitations (e.g., trapezoidal and unit-step). These canonical transient responses are then expressed analytically as closed-form expressions involving ILHIs, CILHIs, and Bessel functions. The DHPPM simulator can simulate transient results for various input waveforms on both single and coupled interconnect structures. Comparisons between the DHPPM results and the results produced by commercial simulation tools like HSPICE and a numerical Inverse Fast Fourier Transform (IFFT) show that the DHPPM results are very accurate.
66

Development of 66 kV and 275 kV Class REBCO HTS Power Cables

Hayakawa, N., Ishiyama, A., Amemiya, N., Hasegawa, T., Saitoh, T., Yagi, M., Mukoyama, S., Ashibe, Y., Masuda, T., Okuma, T., Maruyama, O. 06 1900 (has links)
No description available.
67

Design, Modelling, Fabrication & Testing of a Miniature Piezoelectric-based EMF Energy Harvester

Pollock, Tim 14 May 2014 (has links)
Wireless sensing applications have extended into power transmission line monitoring applications. Minimal power consumption of sensor electronics have enabled kinetic energy harvesting systems to provides a means of self sustainability in the form of parasitic energy harvesting from power transmission lines. With this goal in mind, a miniature piezoelectric bimorph cantilever harvester has been developed using a magnetic tip mass which interacts with the oscillating magnetic flux surrounding power transmission wires. The focus of this thesis is develop an analytical model which can be used to optimize the amount of piezoelectric material to support sensory electronics. Special emphasis has also been placed on magnet orientation and geometry to ensure optimal magnetic flux interaction between input and output mechanisms. A single prototype harvester is designed with an arbitrary piezoelectric material length and experimentally validated at different conductor wire currents. The analytical model shows excellent agreement in frequency prediction for the prototype tested. Two damping techniques are used to experimentally extract modal damping ratios to predict peak mechanical and electrical responses at resonance frequencies. The miniature prototype design is less than 30 mm in length with only 10 mm piezoelectric material to produce a total volume of 154 10^-12 cm^3. The power output is measured at 174.1 W of power when positioned over top a 10 AWG copper conductor a distance of 6 mm with approximately 16 Amps of current passing though the conductor.
68

Conductor and dielectric property extraction using microstrip tee resonators

Fulford, Andrew Richard, Wentworth, Stuart M. January 2005 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.
69

Design of compact and dual-band microwave microstrip balun /

Tan, Song. January 2008 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 69-77). Also available in electronic version.
70

Microwave coplanar waveguide tunable filters using RF MEMS /

Mariani, Michael, January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 90-93). Also available in electronic format on the Internet.

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