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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.
11

Wireless Implantable EMG Sensing Microsystem

Farnsworth, Bradley David 30 July 2010 (has links)
No description available.
12

Modeling Of Helically Applied Current To The Inductively Coupled Radio Frequency Plasma Torch In Two Dimensions

Canturk, Mehmet 01 January 2004 (has links) (PDF)
The electrodeless plasma discharge is typically driven by radio frequency (RF) power supply within the range (0.2 &iexcl / 40 MHz). The applied power is coupled into the plasma inductively called inductively coupled plasma (ICP). RF ICP technique has achieved significance importance in a diversity of research and industrial applications for over the last threes decades. It is still required to undertake both theoretical and experimental research. In this work, RF ICP technique is applied on the torch modeling in 2D. Based on extended electromagnetic vector potential representation, an axisymmetric model in 2D is proposed for the calculations of the electromagnetic fields in an RF ICP torch. The influence of axial vector potential is included to the vector potential formulations. This is achieved by imposing a helical current carrying wire configuration. The corresponding governing equations are solved numerically by applying finite element method (FEM) using commercial partial differential equation solver (Flex PDE3). Based on this model, the plasma behavior and properties are examined in terms of plasma parameters. Besides, a comparative iii analysis is made between proposed model called helical configuration and the one currently available in the literature called circular configuration. This study shows relatively little difference between temperature fields predicted by two models. However, significant difference is observed between corresponding flows and electromagnetic fields. Especially, tangential flow which is observed in helical configuration vanishes in circular configuration. The proposed model offers an effective means of accounting for the variations of the helical coil geometry on the flow and temperature fields and achieving a better representation of the electromagnetic fields in the discharge. Finally, it is concluded that minimum number of turns (n = 2) yields significant difference between two models whereas, maximum allowable number of turns yield no distinctions on the results of two models in terms of azimuthally applied current. However, axial effect of current still exists but very small with respect to the result obtained with minimum number of turns.
13

Caractérisation et modélisation électrique des phénomènes de couplage par les substrats de silicium dans les empilements 3D de circuits intègrés / Characterization and modelling of the coupling effects by the substrates in the stackings up of the 3D integrated circuits.

Eid, Elie 11 May 2012 (has links)
Afin d’améliorer les performances électriques dans les circuits intégrés en 3D, une large modélisation électromagnétique et une caractérisation haute fréquence sont requises. Cela a pour but de quantifier et prédire les phénomènes de couplage par le substrat qui peuvent survenir dans ces circuits intégrés. Ces couplages sont principalement dus aux nombreuses interconnexions verticales par unité de volume qui traversent le silicium et que l’on nomme « Through Silicon Vias » (TSV).L’objectif de cette thèse est de proposer des règles d’optimisation des performances, à savoir la minimisation des effets de couplage par les substrats en RF. Pour cela, différentes configurations de structures de test utilisées pour analyser le couplage sont caractérisées.Les caractérisations sont effectuées sur un très large spectre de fréquence. Les paramètres d’analyse sont les épaisseurs du substrat, les architectures des vias traversant (diamètres, densités, types de barrières), ainsi que la nature des matériaux utilisés. Des modèles électriques permettant de prédire les phénomènes de couplage sont extraits. Différents outils pour l’analyse de ces effets, sont développés dans notre laboratoire. Parallèlement un important travail de modélisation 3D est mené de façon à confronter mesure et simulation et valider nos résultats. Des stratégies d’optimisation pour réduire ces phénomènes dans les circuits 3D ont été proposées, ce qui a permis de fournir de riches informations aux designers. / In order to improve the electrical performance in 3D integrated circuits, a large electromagnetic modeling and a high frequency characterization are required. This has for goal to quantifiy and predicts the substrate coupling phenomena that can occur in these integrated circuits. These couplings are mainly due to the numerous vertical interconnections existing in a small volume and passing through the silicon, and so called “Through Silicon Vias” (TSV). The objective of this thesis is to propose rules for electrical performance optimization, in order to minimize the coupling effects in RF substrates. For this reason, different test structures configurations used to analyze the coupling are characterized.The characterizations are performed on a very wide frequency spectrum. The analysis parameters are the thicknesses of the substrate, the TSV architectures (diameters, densities, types of barriers), and the nature of the used materials. Electrical models for predicting the coupling phenomena are extracted. Different tools for the analysis of these effects are developed in our laboratory. At the same time, a considerable amount of 3D modeling is conducted to compare measurements with simulations and validate our results. Optimization strategies to reduce coupling phenomena in 3D circuits have been proposed; this has provided a wealth of information to designers.
14

Návrh a realizace bezdrátového nabíjení pro vestavěné systémy / Design and implementation of wireless charging for embedded systems

Bednařík, Josef January 2020 (has links)
This thesis deals with the design and realization of wireless power charging circuit for embedded systems. The research section focuses on the various ways and technologies used in applications of wireless power transfer. The theoretical part also briefly characterizes resonant inductive coupling and critical parameters of the transfer. This is followed by realization of various variants of transfer coils and electromagnetic oscillators. Wireless power charging prototype system is created and used for testing purposes to find optimal configuration of resonator. The hardware unit presented in the final part of the thesis exploits microcontroller and implemented software is extended by foreign object detection algorithm along with method to monitor battery charging state.
15

Soft Intelligence : Liquids Matter in Compliant Microsystems

Jeong, Seung Hee January 2016 (has links)
Soft matter, here, liquids and polymers, have adaptability to a surrounding geometry. They intrinsically have advantageous characteristics from a mechanical perspective, such as flowing and wetting on surrounding surfaces, giving compliant, conformal and deformable behavior. From the behavior of soft matter for heterogeneous surfaces, compliant structures can be engineered as embedded liquid microstructures or patterned liquid microsystems for emerging compliant microsystems. Recently, skin electronics and soft robotics have been initiated as potential applications that can provide soft interfaces and interactions for a human-machine interface. To meet the design parameters, developing soft material engineering aimed at tuning material properties and smart processing techniques proper to them are to be highly encouraged. As promising candidates, Ga-based liquid alloys and silicone-based elastomers have been widely applied to proof-of-concept compliant structures. In this thesis, the liquid alloy was employed as a soft and stretchable electrical and thermal conductor (resistor), interconnect and filler in an elastomer structure. Printing-based liquid alloy patterning techniques have been developed with a batch-type, parallel processing scheme. As a simple solution, tape transfer masking was combined with a liquid alloy spraying technique, which provides robust processability. Silicone elastomers could be tunable for multi-functional building blocks by liquid or liquid-like soft solid inclusions. The liquid alloy and a polymer additive were introduced to the silicone elastomer by a simple mixing process. Heterogeneous material microstructures in elastomer networks successfully changed mechanical, thermal and surface properties. To realize a compliant microsystem, these ideas have in practice been useful in designing and fabricating soft and stretchable systems. Many different designs of the microsystems have been fabricated with the developed techniques and materials, and successfully evaluated under dynamic conditions. The compliant microsystems work as basic components to build up a whole system with soft materials and a processing technology for our emerging society.

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