In this dissertation, two important current mode circuit design subjects have been explored. In the first part, the switched-current circuit technique has been investigated. The fundamental performance and limitations of this technique are explored. One of the major limitations, the signal distortion caused by clock feedthrough has been substantially reduced by a newly developed clock feedthrough cancellation technique. In addition, a filter synthesis technique has been developed by directly simulating the structure of digital filter. Several experimental CMOS prototypes have been designed and fabricated. The measured frequency and phase responses demonstrated the feasibility of this synthesis technique. In the second part, a new logic family called current-steering logic has been developed. The fundamental performance and characteristics of this technique have been discussed including the basic inverter and NOR gate with DC analysis, transient analysis and power-delay product. It has been shown that the current-steering logic has, a much smaller current spike than conventional CMOS logic circuits, which is especially desirable in mixed-mode applications. Several experimental prototypes have verified the functionality and performance of this new technique. / Graduation date: 1991

With increasing interest in current-mode analogue processing due to its high performance properties such as speed, bandwidth and accuracy compared to voltage-mode processing, new current-mode alternatives to various conventional circuit designs are appearing. In this report, a novel circuit design to construct a fully-differential current-mode operational amplifier ( OP-AMP ) is suggested. A standard CMOS process and a 5 volt power supply are utilized. Simulation results using SPICE are presented. For the current-amplifier, a highly linear behavior ( THD 0.02% ) and an excellent frequency response ( 10 MHz ) were observed. Using this new differential OP-AMP topology, fully-differential switched-current delay cell and an integrator circuit were also developed successfully. / Graduation date: 1991

L'échantillonneur-bloqueur est un dispositif central des systèmes de conversion analogique-numérique. Son utilisation dans des domaines d'applications sensibles comme le domaine biomédical place des exigences élevées sur la performance de l'échantillonneur. Les distorsions d'injection de charges, d'erreur d'échantillonnage et celle due aux variations de la constante de temps sont trois sources de non-linéarité qu'il est primordial d'évaluer pendant la conception. La modélisation analytique est l'une des méthodes employées afin d'estimer la distorsion du dispositif d'échantillonnage. Cependant, les méthodes analytiques courantes sont complexes ou ne tiennent pas compte des capacités parasites du commutateur analogique. La conception par la mise en oeuvre de procédures de caractérisation de la distorsion à l'aide de simulateurs analogiques de la famille SPICE donne une bonne estimation de la distorsion mais aboutit à des cycles de conception longs et fastidieux. Dans ce document, nous proposons deux méthodes d'évaluation de la distorsion de l'échantillonneur-bloqueur. Dans un premier temps, nous présenterons un nouveau modèle analytique simple de la distorsion. Notre modèle met en oeuvre l'approximation en série de Taylor afin de caractériser complètement les trois sources de distorsion de l'échantillonneur-bloqueur, incluant l'effet de substrat et les capacités parasites du commutateur analogique. Une autre contribution dans ce mémoire est de proposer un logiciel de simulation comportementale d'aide à la conception des échantillonneurs-bloqueurs dans le procédé MOS submicronique 0.18 µm. Ce logiciel permet de réduire le cycle de conception et d'évaluer efficacement la distorsion de l'échantillonneur-bloqueur. Afin d'atteindre cet objectif, nous avons intégré le modèle BSIM3 du transistor au logiciel que nous avons développé en langage Java. Nous verrons avec des exemples d'application comment les paramètres de chacune des sources de distorsion agissent sur la gamme dynamique de l'échantillonneur-bloqueur par les méthodes que nous proposons. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Échantillonneur-blogueur, Distorsion, CMOS, Modélisation comportementale.

Le besoin de concevoir des systèmes de détection efficaces de diverses substances afin d'améliorer le contrôle de qualité et la sécurité environnementale, nous amène à chercher de nouvelles approches pour contourner les problèmes reliés aux systèmes de détection actuels, tels leur taille, coût, sélectivité et consommation d'énergie. Il est aussi souhaitable de définir un modèle de développement qui ne soit pas contraint par le besoin d'une connaissance précise des processus physiques sous-jacents, souvent inconnus. Ce mémoire décrit la mise en oeuvre partielle d'un dispositif permettant d'identifier et de mesurer la concentration de substances fluorophoriques dans un milieu optique typique (Solution liquide ou suspension dans un fluide). La méthode est basée sur des mesures de fluorescence multispectrales, réalisées en excitant une substance inconnue avec une ou plusieurs diodes électroluminescentes qui couvrent un intervalle de longueurs d'ondes donné. La conception du détecteur photoélectrique repose sur la propriété inhérente des diodes électroluminescentes d'agir comme détecteurs photoélectriques quand elles sont polarisées à l'envers, et cela en offrant une réponse spectrale qui dépend de leur couleur. Dans ce mémoire, on propose un système dont l'entrée est composée d'une diode excitatrice et d'un ensemble de diodes électroluminescentes de différentes couleurs qui détectent la lumière à différentes longueurs d'ondes. Les données acquises par les photodiodes sont transmises à un système d'amplification puis à un convertisseur analogique numérique avant d'être acheminées vers un microcontrôleur implémenté sur une puce FPGA. Ce dernier permet de commander le processus de saisie des données et l'affichage des résultats obtenus quant au type et à la concentration des données obtenues. Un réseau de neurones artificiel (RNA) codé en logiciel réalise le traitement des données requis. Ce mémoire couvre tous les aspects du design sauf celui du RNA. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Mesure de fluorescence, Photodiode, FPGA, MicroBlaze.

For predictive maintenance of circuit breakers, a number of variables must be considered in order to assess the genuine working condition of a circuit breaker [CB]. This thesis selects vibration signatures obtained on the operating mechanisms and arcing chambers as a source of monitoring breaker conditions. The task of analyzing the behavior of a circuit breaker is perennial and difficult but the thesis has an attempt to tackle this problem. Experiments have been devised to monitor CBs; however, these have limitations details of which will be discussed. For example, each circuit breaker has its own unique vibration signature and the shape of the vibration may be different even though breakers confront similar problems. CBs have decades-long service life spans and failure rates are relatively low. Those that fail are not necessarily saved and there have been relatively few samples to base evidence upon. There are different vibration analysis algorithms available including Dynamic Time Warping [DTW], Resolution Ratio [RR], Discrete Envelope Statistics [DES], event time extraction, Chi-square based shape methods, and fractal theory. Some of these algorithms are based on acoustic properties of materials and rely on assessing extracted time component and the frequency components are extracted. This research applies multi-resolution analysis [MRA] to decomposed signals to in order to assess different sub-wave levels so that wave features may be captured and modeled. There are many ways to analyze the waves. This thesis uses optimizing fuzzy rules with genetic algorithm [GA] as the proposed method. The simuation part of the thesis uses spring performance as an example of how vibration signature analysis may be implemented. Spring vibrations are evaluated by two classification algorithms: Dynamic Time Warping [DTW] and multi-resolution analysis [MRA] with optimizing fuzzy rules with genetic algorithm [GA]. The first method is competent to identify the faulty cases from the normal ones by looking at the deviation of the vibration signature frequency content. In contrast, it is not capable to identify the degree of how bad it performs from looking at the frequency variation. For the second method, it is capable of not only classifying the abnormal cases from the normal cases, but also distinguishing the vibration signatures into different category so that the spring condition can be retrieved immediately. Fuzzy rules is capable of classify a new case to a category and genetic algorithm is an effective tool to minimize the applicable fuzzy rules. The accuracy of the identification is very satisfactory, which is over 90%. Consequently, the proposed algorithm is very useful for asset management purpose of breaker since the lifespan of the spring is known. Diagnostic technicians are able to make decision on the replacement scheme of the spring. There are some areas that this research uncovered that suggests further study is mandated. For example, there are other parameters that can be monitored and compared other than spring constant such as valve position in trip coil and close coil, acceleration parameter in changeover valves, damping in hydraulic cylinders and mechanical linkages, gas pressure in primary contacts and breaker resistance in line system.

With smaller electronic devices and higher transmission speeds, a digital circuit will cause potential electromagnetic interference (EMI) and signal integrity (SI) problems. Nowadays, the flexible printed circuit board (FPC) is widely used in electronic systems, especially in the video circuit. In this thesis, we used transmission line model to explain effect of the structure of the flexible printed circuit board transmission lines. Eye-diagram is a fast and convenient tool to analyze the quality of the high speed transmission, and we can use the equivalent model to substitute for the electromagnetic (EM) model to simulate the performance. We used differential circuit and the reflection gain to increase the height and width parameters of Eye-diagram, and make the quality of signal transmission higher. For video driver circuit, since the terminal resistance is different depending on whether the IC is on or off, the standard probe cannot measure mixed-mode S-parameter directly due to the connectors. Thus, we provided a de-embedding method to remove the effects of high speed interconnect line on the test board. Finally, we use a simple structure to verify the method, and it can be used to measure mixed-mode S-parameter on the standard of Mobile Industry Processor Interface (MIPI) for D-PHY, v0.90.00.

In this dissertation, multiband ground antennas for slim handsets are presented. The design techniques are on efficiently exciting the resonant modes of the system ground plane of the handset to greatly enhance the antenna¡¦s operating bandwidth. The first antenna design is a monopole antenna integrated with a slot antenna formed in a clearance in the system ground plane to enhance the bandwidth of the antenna¡¦s lower band for penta-band WWAN operation. The second antenna design uses a shaped circuit board with a proper notch embedded therein to result in stronger surface current excitation in the ground plane, which leads to bandwidth enhancement in the antenna¡¦s lower band and upper band. The second antenna design can cover seven-band WWAN/LTE operation. The antenna geometry in the second antenna design is further applied in the third antenna design. In order to meet the practical application of slim handsets, the third antenna design is integrated with a battery element and a metal midplate to decrease the thickness of the handset. The third antenna design can cover seven-band WWAN/LTE operation. Finally, the simulated SAR and HAC results are analyzed for the three proposed antennas.

Gate sizing and threshold voltage (Vt) assignment are very popular and useful techniques in current very large scale integration (VLSI) design flow for timing and power optimization. Lagrangian relaxation (LR) is a common method for handling multi-objectives and proven to reach optimal solution under continuous solution space. However, it is more complex to use Lagrangian relaxation under discrete solution space. The Lagrangian dual problem is non-convex and previously a sub-gradient method was used to solve it. The sub-gradient method is a greedy approach for substituting gradient method in the deepest descent method, and has room for further improvement. In addition, Lagrangian sub-problem cannot be solved directly by mathematical approaches under discrete solution space. Here we propose a new Lagrangian relaxation-based method for simultaneous gate sizing and Vt assignment under discrete solution space. In this work, some new approaches are provided to solve the Lagrangian dual problem considering not only slack but also the relationship between Lagrangian multipliers and circuit timing. We want to solve the Lagrangian dual problem more precisely than did previous methods, such as the sub-gradient method. In addition, a table-lookup method is provided to replace mathematical approaches for solving the Lagrangian sub-problem under discrete size and Vt options. The experimental results show that our method can lead to about 50 percent and 58 percent power reduction subject to the same timing constraints compared with a Lagrangian relaxation method using sub-gradient method and a state-of-the-art previous work. These two methods are implemented by us for comparison. Our method also results in better circuit timing subject to tight timing constraints.

In traditional Chinese herb medicine, Alismatis rhizoma has been used in treating edema, inflammation and increasing urine flow. Mechanism of Alismatis rhizoma¡¦s effect on these functions has not been elucidated. Since diuresis has been considered closely related to the reabsorption of sodium ion via the epithelium of tubule and collecting duct in kidney, we suspected that Alismatis rhizoma may influence transportation of salt and water. The measurement of short circuit current ( Isc ) has been used widely to estimate the ion transportation between mucosal and serosal side of epithelium. In the present experiment, we used the voltage ¡V clamp technique to demonstrate the effect of Alismatis rhizoma¡¦s extracts ( ARE ) on Isc and sodium ion conductance in frog skin. Our result showed that in control stage, the potential difference ( PD ) of frog skin is 64.81 ¡Ó 2.44 mV, the Isc is 59.82 ¡Ó 3.58 £gA / cm2 and the conductance is 1.09 ¡Ó 0.18 £gA / cm2 / mV. After ARE was applied to mucosal side of the frog skin, its Isc decrease from 62.63 ¡Ó 5.31 £gA / cm2 to 47.92 ¡Ó 5.41 £gA / cm2, which could further go down to 3.36 ¡Ó 1.06 £gA/cm2 by adding amiloride. Treating serosal side of frog skin with ARE decreased approximately 10% of its Isc. No apparent changes in conductance were observed by adding ARE to mucosal ( 0.98 ¡Ó 0.24 £gA / cm2 / mV ) or serosal side ( 0.96 ¡Ó 0.23 £gA / cm2 / mV ). Adding L-arginine ( the precursor of nitric oxide ) to the serosal side of the skin epithelium elevated the Isc for 17.10 ¡Ó 9.30 £gA/cm2. This effect can be inhibited by applying ARE or NG-L-nitro-arginine methyl ester ( L-NAME, NO synthase inhibitor ) before application of L-arginine. In summary, Alismatis rhizoma could affect Isc on both mucosal and serosal sides of the frog skin. Its effect on lowering Isc was more obvious when applied to the mucosal side than to the serosal side. The ARE may exert its effect on mucosal side by affecting amiloride¡Vsensitive sodium channel and on serosal side by affecting the NO signal transduction pathway.

MOSFET-C filters is popular in analog filters, the major reason is the simplicity. They are easily implemented with opamps and have similar architectures to active RC filters [1], this saves much of the design time. The frequency response of analog continuous time filters is determined by resistors, capacitors, inductors or transconductors. However, the process variation, temperature drift and aging, make the integrated RC time constants vary about 30 percent [2]~[3]. We proposed a switched-capacitor tuning circuit , which can be used in MOSFET-C Filter and the novel tuning circuit doesn¡¦t need off chip capacitor. The novel circuit has following advantages (1). Small chip size. (2). Simplicity (3). Low reference clock frequency.