Depuis 1965, la loi de Moore, loi de doublement du nombre de transistors dans une puce tous les deux ans, n’a jamais été contredite. II faut attendre septembre 2007 pour que son inventeur lui-même, Gordon Moore, ne la considère plus valide et estime sa fin dans les dix à quinze ans à venir. Le problème des limites physiques de la technologie CMOS actuelle est alors aujourd’hui posé : jusqu’où la miniaturisation peut-elle continuer? Combien d'atomes faut-il pour faire un transistor fonctionnel ? Y a-t-il d'autres matériaux que les semiconducteurs qui permettraient d'aller au delà des limites physiques, ou encore d'autres moyens de coder l'information de façon plus efficace? La technologie des transistors à un électron (SET, Single Electron Transistor) est une des solutions possible et semble très prometteuse. Bien souvent cantonné à un fonctionnement bien en dessous de la température ambiante, les premiers SETs métalliques démontrant un caractère typique de blocage de Coulomb à des températures dépassant 130 °C sont une des premières réussites du projet "SEDIMOS" ici à l'Université de Sherbrooke. Véritable couteau-suisse, le SET présente des caractéristiques électriques qui vont au delà de la technologie CMOS actuelle tout en pouvant copier cette dernière sans grande difficulté. Dans un circuit, il faut cependant lui adressé [i.e. adresser] certains problèmes tel [i.e. tels] qu’un faible courant de commande, un faible gain en tension et un délai important. Mais tous ces aléas peuvent être cependant contournés ou réduits par une conception adaptée de ces circuits. Cependant, il existe une difficulté à fabriquer de multiples SETs ayant des caractéristiques électriques similaires. En outre, les circuits peuvent exiger des SETs avec un haut niveau de performance. Souhaitant repousser les limites actuelles de la logique SET, le but de cette maîtrise est de réaliser un inverseur SET développant principalement les deux caractéristiques critiques mentionnées dans le paragraphe précédent. Sous un travail à température ambiante, voir supérieur, l'inverseur devra développer un gain en tension supérieur à l'unité. Les SET métalliques présentés dans ce travail sont fabriqués sur un substrat de silicium oxydé par oxydation sèche. Le procédé de fabrication utilisé est cependant compatible avec l'unité de fabrication finale du CMOS, Back End of Line (BEOL). Un coût réduit, un faible bilan thermique, et une amélioration de la densité d'intégration dans le cadre d'une production de masse de circuits hautement intégrés rendent ce procédé de fabrication très attrayant. L'objectif principal de cette maîtrise peut être divisé en 3 parties : (1) L'étude des paramètres électriques tels que les tension, gain, capacité d'attaque et puissance du circuit inverseur SET, (2) l'amélioration des performances de la logique SET grâce à la modification des paramètres physiques des SETs et de l'architecture de leurs circuits et (3) la présentation des résultats de mesures électriques.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / A method for combining telemetry data and quantifying the resulting coding gain for a ballistic missile test flight is presented. Data received from five ground stations in 54 data files with 18 million intermittent frames is combined, to create a single file with 1.5 million continuous frames. Coding gain provided by data combining is as high as 30 dB, with a useful improvement of 5 dB at boost and terminal stages. With frame reconstruction techniques, erroneous words in a frame are reduced from 2.1% to 0.12 %.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / PSK demodulators have been an integral part of the signal recovery process for decades. Unless a person has designed a demodulator, how much can a person know or understand about its operation? Instruction on how to set up a demodulator’s parameters to acquire a signal is found in a manual. An explanation of why parameters are set a certain way to handle particular input signal characteristics is often not provided in a manual. This paper is designed to be a tool to aid engineers, technicians, and operators who utilize demodulators. Its purpose is to relay the functionality of a demodulator to a user so that he or she can take advantage of its control parameters and status feedback. Knowing the reasons why a demodulator is set to certain parameters may greatly reduce confusion when a system is not working properly. On site troubleshooting may be accomplished without the need to call the manufacturer of the product. Another advantage of understanding the operation will be recognized when interfacing with the manufacturer. A person will be able to relay the information to a design engineer more easily, and will understand more of the engineer’s feedback on the potential problem. Utilizing this paper as an aid to enhance operation of a PSK demodulator will bring a user one step closer to understanding the complexity of its design.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / This paper presents a new variable beamwidth antenna designed for use in telemetry tracking systems when a high gain/low gain antenna configuration is required. This antenna can be commanded to continuously vary its beamwidth between a high gain/narrow beamwidth mode of operation and a low gain/ wide beamwidth mode of operation. A design goal of a 4:1 increase in beamwidth has been set and a 3.0:1 increase has been achieved without causing any significant degradation in the shape of the antenna patterns and without generating exceedingly high sidelobes in the low gain setting. The beamwidth variation occurs continuously without any loss of data, boresight shift or jitter such as experienced with the operation of conventional implementations of the high gain/low gain antenna technique.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / This paper reports the analysis of L-band channel sounding experiments conducted along the flight line at Cairns Army Airfield, Ft. Rucker, Alabama. Propagation data from multiple antennas on a helicopter to multiple receiving antennas on the ground are used to compute power delay profiles. Analysis of the results reveals delay spreads of the multipath channels between 200 ns and 400 ns, with the longer delay spreads resulting when using a receive antenna with lower gain and higher sidelobe levels. The data also shows that on average, diversity signaling from three aircraft-mounted antennas can lead to gains in signal-to-noise ratio of approximately 13 dB, with the gain dependent on the multipath characteristics observed by the ground antenna.

This thesis details the design and construction of an experiment to measure the radial distribution of laser gain in a cylindrical Helium-Neon laser gain tube. This distribution is important as it can effect the transverse mode structure of a running ring laser. Earlier theoretical models of the distribution were not supported by high quality experimental data and fail to take into account some physical processes. A resolution of 8 parts per million in gain and 50 μm in radial position has been achieved. Gain distributions have been measured and are shown to be well modeled by a 0th order Bessel function with first roots at the tube walls and a central dip depending on excitation power; except for the region very near to the tube walls where a very rapid increase in gain has been observed. Hydrogen has been identified by spectroscopic analysis as the primary constituent of gas contamination and cause of the long term reduction in gain of large ring lasers. Additional work has been done to detect a proposed non-classical Lense-Thirring field around a spinning lead superconductor. It was found that any effect is at least 20 times smaller than predicted. Techniques and tools for data acquisition programming have been reviewed focusing on difficulties with coupling of user interface and application logic, monolithicity, difficulties with scripting and algorithm implementation.

In this thesis, three broadband low-noise mixing circuits which use CMOS 130 nm technology are presented. As one of the first few stages in a receiving front-end, stringent requirements are posted on mixer performance. The Gilbert cell mixers have presented excellent properties and achieved wide applications. However, the noise of a conventional active Gilbert cell mixer is high. This thesis demonstrates both passive and active mixing circuits with improved noise performance while maintaining the advantages of the Gilbert cell-based mixing core. Furthermore, wide bandwidth and variable gain are implemented, making the designed mixers multi-functional, yet with compact sizes and low power consumptions. The first circuit is a passive 2x subharmonic mixer that works from 4.5 GHz to 8.5 GHz. The subharmonic mixing core is a two-stage passive Gilbert cell driven by a quadrature LO signal. Together with a noise-cancelling transconductor and an inverter-based TIA, this subharmonic mixer possesses an excellent broadband conversion gain and a low noise figure. Measurement results show a high conversion gain of 16 dB and a low average DSB NF of 9 dB. The second design is a broadband low-noise variable gain mixer which operates between 1 and 6 GHz. The transconductor stage is implemented with noise cancellation and current bleeding techniques. Series inductive peaking is used to extend the bandwidth. Gain variation is achieved by a current-steering IF stage. Measurements show a wide gain control range of 13 dB and a low noise performance over the entire frequency and gain range. The lowest DSB NF is 3.8 dB and the highest DSB NF is 14.2 dB. The Third design is a broadband low-noise mixer with linear-in-dB gain control scheme. Using the same transconductance stage with the second circuit, this design also works from 1 to 6 GHz. A 10 dB linear-in-dB gain control range is achieved using an R-r load network with a linear-in-dB error less than $\pm$ 0.5 dB. Low noise performance is achieved. For different frequencies and conversion gains, the lowest DSB NF is 3.8 dB and the highest DSB NF is 12 dB. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-10-02 04:37:31.606

In the chemical or biochemical industry most processes are modeled by nonlinear equations. It is of a great significance to design high-performance nonlinear controllers for efficient control of these nonlinear processes to achieve closed-loop system's stability and high performance. However, there are many difficulties which hinder the design of such controllers due mainly to the process nonlinearity. In this work, comprehensive design procedures based on robust control have been proposed to efficiently deal with the design of gain-scheduled controllers for nonlinear systems. Since all the design procedures proposed in this work rely strongly on the process model, the first difficulty addressed in this thesis is the identification of a relatively simple model of the nonlinear processes under study. The nonlinearity of the processes makes it often difficult to obtain a first-principles model which can be used for analysis and design of the controller. As a result, relatively simple empirical models, Volterra series model and state-affine model, are chosen in this work to represent the nonlinear process for the design of controllers. The second major difficulty is that although the nonlinear models used in this thesis are easy to identify, the analysis of stability and performance for such models using nonlinear control theory is not straightforward. Instead, it is proposed in this study to investigate the stability and performance using a robust control approach. In this approach, the nonlinear model is approximated by a nominal linear model combined with a mathematical description of model error to be referred to, in this work, as model uncertainty. In the current work it was assumed that the main source of uncertainty with respect to the nominal linear model is due to the system nonlinearity. Then, in this study, robust control theoretical tools have been especially developed and applied for the design of gain-scheduled Proportional-Integral (PI) control and gain-scheduled Model Predictive Control (MPC). Gain-scheduled controllers are chosen because for nonlinear processes operated over a wide range of operation, gain-scheduling has proven to be a successful control design technique (Bequette, 1997) for nonlinear processes. To guarantee the closed-loop system's robust stability and performance with the designed controllers, a systematic approach has been proposed for the design of robust gain-scheduled controllers for nonlinear processes. The design procedure is based on robust stability and performance conditions proposed in this work. For time-varying uncertain parameters, robust stability and performance conditions using fixed Lyapunov functions and parameter-dependent Lyapunov functions, were used. Then, comprehensive procedures for the design and optimization of robust gain-scheduled PI and MPC controllers tuning parameters based on the robust stability and performance tests are then proposed. Since the closed-loop system represented by the combination of a state-affine process model and the gain-scheduled controller is found to have an affine dependence on the uncertain parameters, robust stability and performance conditions can be tested by a finite number of Linear Matrix Inequalities (LMIs). Thus, the final problems are numerically solvable. One of the inherent problems with robust control is that the design is conservative. Two approaches have been proposed in this work to reduce the conservatism. The first one is based on parameter-dependent Lyapunov functions, and it is applied when the rate of change of the time-varying uncertainty parameters is <i>a priori</i> available. The second one is based on the relaxation of an input-saturation factor defined in the thesis to deal with the issue of actuator saturation. Finally, to illustrate the techniques discussed in the thesis, robust gain-scheduled PI and MPC controllers are designed for a continuous stirred tank reactor (CSTR) process. A simple MIMO example with two inputs and two outputs controlled by a multivariable gain-scheduled MPC controller is also discussed to illustrate the applicability of the methods to multivariable situations. All the designed controllers are simulated and the simulations show that the proposed design procedures are efficient in designing and comparing robust gain-scheduled controllers for nonlinear processes.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The general aims of the thesis were to study GH responsiveness by estimation of pharmacokinetics and bioavailability of injected recombinant human GH (rhGH), of growth response as gain in heightSDS during childhood and puberty, and IGF-I response as change in circulating IGF-ISDS and IGFBP3SDS. Methods Short children were recruited during 1988–1999 into two national randomized multicentre clinical trials on growth until adult height. A group of 117 GHD patients who had been treated from prepuberty with a single GH dose of 33μg/kg/day for at least 1 year were randomized at onset of puberty either to remain on this dose regimen or to an increased dose, GH67μg/kg/day, administered once daily or divided into two doses, GH33x2μg/kg/day. Data on IGF-ISDS and IGF binding protein 3 (IGFBP3)SDS were available from 111 patients and analysed as stated below. The 151 short prepubertal non-GHD patients were randomized into three groups: untreated controls, GH33 or GH67μg/kg/day. A subpopulation from both trials, 128 patients examined annually in Gothenburg, formed the study sample on GH uptake. They received sc GH injections to obtain 16–24 hour GH curves and the GH pharmacokinetics and bioavailability was calculated. Results: A dose-dependent effect on Cmax was found with great intra- and inter-individual variability. Of the Cmax variability, 43% was explained by the rhGH dose and proxies for injection depth. Median bioavailability of the injected dose was 71%, with great variation, mainly dependent on injection depth. In the IGHD group a dose-dependent difference in pubertal gain in heightSDS was found, with mean of 0.8 for the GH67 group and 0.4 for GH33, p&lt;0.01. The mean total gain in heightSDS during treatment was 1.9 for GH67 and 1.4 for GH33, p&lt;0.01. A dose-dependent pubertal ΔIGF-ISDS was 0.5 vs −0.1, p=0.007, correlating to pubertal gain in heightSDS, p=0.003; and was the most important variable to explain the variation in pubertal gain in heightSDS. In the non-GHD group the ΔIGF-ISDS from baseline to mean study level was dose-dependent 2.07 vs 1.20, p=0.001; and correlated negatively with baseline values of IGF-ISDS, rho= -0.56 for GH67, p=0.001, vs rho= -0.82 for GH33, p=0.0001, and correlated positively with gain in heightSDS in both GH-treated groups, rho= 0.42, p&lt;0.001. In multivariable regression analyses, ΔIGF-ISDS was always an important explanatory variable for long-term growth response from the prepubertal period until adult height, while the IGF-ISDS study level per se was not. Conclusion: Growth response to GH treatment was dose dependent with great variability between patients. More pubertal growth was attained by an increased rhGH dose, mimicking the physiology of healthy children, in whom GH secretion rate increases during puberty. This resulted in a gain in IGF-ISDS closely correlating to pubertal gain in heightSDS in both IGHD and non-GHD patients. A broad range in GH responsiveness was found for both growth and IGF response in both diagnostic groups, but lower in the non-GHD group. Higher uptake of a given GH dose was observed after a deep injection and a higher GH concentration. These results are clinically applicable for individuals who remain short close to onset of puberty; by identifying and deeply injecting a rhGH dose that accounts for individual responsiveness, we can stimulate an increment in IGF-ISDS that correlates to gain in heightSDS during puberty.