Human brain and related topics like neuron spikes and their active potentials have become more and more attractive to people these days, as these issues are extremely helpful for curing many neural injuries and cognitive diseases. One method to discover this field is by designing a chip embedded in brains with probes to actual neurons. It is obvious that batteries are not practical for these applications and thereby RF radiation is used as power sources, revealing that chips should operate under a very low power supply. Since neural signals are analog waveforms, analog-to-digital converter (A/D converter, ADC) is the key component in a neural recorder chip. This thesis proposes the complete design of a low power 8-bit successive approximation register (SAR) A/D converter for use in a wireless neural recorder chip, realizing the function of digitizing a sampled neural signal with a frequency distribution of 10Hz to 10kHz. A modified energy-saving capacitor array in the SAR structure is provided to help save power dissipation. Therefore, the ADC shall operate within a power budget of 20­μW maximum from a 1­V power source, at a clock frequency of 500kHz corresponding to a conversion rate of 55.5-kS/s. All the circuits are designed and implemented based on the IBM/Global Foundries 8HP 130nm BiCMOS technology. Simulations of schematic and layout versions are done respectively to verify the functionality, linearity and power consumption of the ADC. Key words: Successive approximation register analog-to-digital converter (SAR-ADC), low power design, energy-saving capacitor array, neural recorder applications

A meta do trabalho é propor e testar a hipótese que a contagem de tráfego nas interseções da rede de transportes, ao invés de contagem de tráfego nos arcos, reduz o grau de indeterminação e torna mais precisa a matriz OD estimada pelo modelo sintético. Ademais, é proposto e detalhado um método de estimação da matriz OD através de médias sucessivas (MEMS). É apresentada a descrição matemática das propostas e o detalhamento dos experimentos elaborados para testá-las. Três métodos de estimação, QUEENSOD, TransCAD e MEMS, foram utilizados na verificação da hipótese. A inserção de \"arcos virtuais\" na rede de transportes constituiu um artifício que permitiu aos programas QUEENSOD e TransCAD realizarem a estimação utilizando fluxos observados nas interseções. A utilização de contagens de fluxo nas interseções propiciou à matriz OD estimada, melhorias que acarretaram sua aproximação com a matriz OD \"real\". O experimento mostrou que a matriz OD estimada ao considerar contagens de tráfego nas interseções apresenta melhor desempenho em comparação a matriz estimada ao considerar contagens nos arcos da rede de transportes. A matriz estimada gradativamente aproximou-se da \"real\" à medida que foi aumentada a quantidade de informação de fluxo e sua distribuição na rede. Assim, a hipótese formulada para este trabalho não pôde ser refutada. / The aim of this work is to propose and test the hypothesis that traffic counts collected at network intersections, instead of traffic counts collected at links, reduce indeterminacy and make more accurate the OD matrix estimated by the synthetic model. Furthermore, a method is proposed and described in detail to estimate the OD matrix based on successive averages (MEMS). The model formulation of the proposals and a description of the experiments are presented. Three estimation methods, QUEENSOD, TransCAD, and MEMS were used in the hypothesis verification. The use of \"virtual links\" in the network consists of an artifice that enable the QUEENSOD and TransCAD to estimate the OD matrix based on traffic counts at intersection. By using flow counts conducted at intersections, improvements could be made to the estimated OD matrix bringing it closer to \"real situations\". The experiments results show that the OD matrix estimation based on traffic counts collected on network intersection has a better performance in contrast to the estimation based on traffic counts collected on network links. The estimated matrix gradually becomes closer to \"real situations\" while the quantity of information flow and its distribution to the network is increased. Therefore, the formulated hypothesis for this work cannot be refuted.

O Contraste Sucessivo é um dos paradigmas experimentais que modelam a experiencia de perda. Nele, os organismos deixam de estarem expostos à eventos reforçadores, apetitivos e/ou preferidos para entrarem em contato com outros de menor qualidade ou valor. Isto resulta numa série de estratégias comportamentais caracterizadas por um importante componente emocional, uma diminuição na execução da resposta (consumatória ou operante) que não está mais correlacionada com a consequência, um aumento na execução de respostas que eram menos prováveis, e uma conservação da estrutura do comportamento exibido antes da perda ou deterioro. A função dos estímulos antecedentes e/ou discriminativos envolvidos, que constituem a parte vigente da contingência que foi quebrada, também tem se mostrado comprometida. Contudo, a interação entre essas características tem sido estudada de modo separado, seja por complicações técnicas ou por isolamento teórico entre os paradigmas. Neste experimento se apresenta uma proposta que tenta obter uma caracterização mais abrangente das estratégias comportamentais que emergem numa situação de perda, aproveitando a versatilidade topológica e funcional da resposta ocular, e a disponibilidade de recursos técnicos que permitem obter medidas precisas dela. Para isso, no procedimento utilizado foram disponibilizadas alternativas de resposta com diferentes valores de reforçamento em cada. 192 fotografias do IAPS foram categorizadas segundo seu valor emotivo e seu conteúdo em seis categorias: Eróticas, Filhotes (Agradáveis), Paisagens naturais, Paisagens artificiais (Neutrais), Doenças e Violência (Desagradáveis). Pares dessas fotografias foram apresentadas num arranjo de quatro quadrantes na tela do computador, antecedidas de forma consistente por Figuras geométricas específicas para cada categoria, enquanto os tempos de fixação eram registrados com um rastreador ocular. Uma sétima figura geométrica foi pareada aleatoriamente com fotografias de todas as categorias. Após atingir um critério de estabilidade baseado no ranqueamento e correspondência entre os tempos de fixação das Figuras geométricas e das Fotografias, as Fotografias da categoria mais observada foram substituídas por Fotografias daquela correspondente ao terceiro lugar, mas continuaram sendo antecedidas pela mesma Figura geométrica. Os resultados mostraram que o procedimento foi sensível às condições e a manipulação experimental. Foi possível estabelecer um ranqueamento entre as categorias a partir das respostas oculares e caracterizar um padrão de observação após a incongruência introduzida. No caso, as preferências exibidas pela participante foram reorganizadas, com um aumento nos tempos de fixação das categorias agradáveis, evitação das fotografias da categoria Doença enquanto a Figura geométrica que à antecedia começou a ser mais observada, e um aumento no tempo de fixação da categoria de imagens aleatórias. No caso das Categorias alteradas, as fotografias de Filhotes (terceira categoria no ranqueamento) que começaram a ser antecedidas pela Figura geométrica correspondente à categoria Violência (a mais observada), foram menos observadas do que àquelas antecedidas pela figura geométrica treinada na fase anterior. São discutidas as melhoras que o procedimento poderia ter assim como o uso das medidas mais apropriadas na exploração de diversos fenômenos comportamentais. Se analisa se os resultados podem ser entendidos dentro do paradigma de contraste e por último se apresentam comentários sobre a necessidade de aproveitar os desenvolvimentos técnicos que permitem executar experimentos mais complexos / Successive Contrast is one of the experimental paradigms that models the experience of loss. On it, organisms are no longer exposed to reinforcing, appetitive and/or preferred events, but to some others with less quality or value. This results in different behavioral strategies characterized by an important emotional component, a decrement in the response not any longer associated with the consequence (consummatory or operant), an increment in less likely responses, and a preservation of behavioral structure from before the impairment. The role of the antecedent and / or discriminative stimuli involved, which constitute the current part of the contingency that has been broken, has also shown to be compromised. However, the interaction between these characteristics has been studied separately, either by technical complications or by theoretical isolation between paradigms. In this study, we propose a procedure to obtain a more comprehensive characterization of the behavioral strategies that emerge in a situation of loss, taking advantage of the topological and functional versatility of the ocular response, and the availability of technical resources that allow to obtain precise measurements of it. To solve this, alternatives for responding with different values of reinforcement were available. 192 photographs from the IAPS were categorized into six categories according to their emotional value and their content: Erotic, Puppies (Pleasant), Natural Landscapes, Artificial Landscapes (Neutral), Diseases and Violence (Unpleasant). Pairs of these photographs were presented in a four-quadrant arrangement on the computer screen, consistently preceded by specific geometric figures for each category, while fixation times were recorded with an eye tracker. A seventh geometric figure was randomly paired with photographs of all categories. After reaching a stability criterion based on the ranking and correspondence between the fixation times of the Geometric Figures and the Photographs, the Photographs of the most observed category were replaced by Photographs of the one corresponding to the third place, but continued to be preceded by the same Geometric Figure. The results showed that the procedure worked well within our experimental conditions and manipulation. It was possible to establish a ranking from the ocular responses among the categories and to characterize a pattern of observation after the introduced incongruity. The preferences exhibited by the participant were reorganized, with an increase in the fixation time of the pleasant categories, avoidance of photographs of the category Disease while its geometric Figure became more observed, and an increase in the fixation time of the category of random images. On the changed Categories, the photographs of Pups (third category in the ranking) that began to be preceded by the geometric Figure corresponding to the category Violence (the most observed category), were less observed than those preceded by the geometric figure trained in the previous phase. The improvements that the procedure could have as well as the use of the most appropriate measures in the exploration of several behavioral phenomena are discussed. It is analyzed if the results can be understood within the contrast paradigm and finally comments are made on the need to take advantage of the technical developments that allow to execute more complex experiments

Menispermaceae é uma família de distribuição pantropical que compreende diversos hábitos, em sua maioria, trepadeiras herbáceas e lianas, além de ervas, arbustos e árvores e onde se faz presente a variação cambial do tipo câmbios sucessivos. Este trabalho apresenta um estudo anatômico do caule e da raiz com ênfase nas lianas e trepadeiras herbáceas. Estudou-se 10 gêneros, 14 espécies e 31 espécimes. Cinco espécies são trepadeiras herbáceas, uma é herbácea (Cissampelos ovalifolia), uma é arbustiva (Abuta grandifolia), e o restante são lianas. As lianas e o arbusto apresentam em seus caules, a variação cambial do tipo câmbios sucessivos, enquanto as trepadeiras herbáceas e a erva não apresentam essa variação estrutural. Demonstra-se na liana Abuta imene, de maneira inédita para a família, que o periciclo origina o tecido conjuntivo, e esse, por sua vez, os câmbios sucessivos. Na análise comparativa do xilema secundário em diversos anéis sucessivos contidos no mesmo caule, destaca-se que o lenho produzido pelos novos anéis vasculares, normalmente, não difere qualitativamente do anel vascular original, no entanto há diferenças quando aos caracteres quantitativos: os diâmetros dos elementos de vasos sofreram aumento estatisticamente significativo no sentido centro-periferia. A análise do caule entre dois hábitos de Abuta grandifolia (liana X arbusto) mostrou que ambos possuem o mesmo padrão anatômico, porém, destaca-se que os diâmetros de elementos de vasos são menores no arbusto. Variações quantitativas ocorrem entre o lenho de caule e a raiz de trepaderias herbáceas e estão relacionadas ao diâmetro e comprimento dos elementos de vasos que são maiores nos caules. Alguns dados são relatados, pela primeira vez, para essa família: (1) Classifica-se o sistema subterrâneo de Disciphania hernandia como raiz tuberosa; (2) Ruptura do raio vascular através da transformação de iniciais radiais em iniciais fusiformes no xilema e floema; (3) A constatação de câmbios sucessivos na raiz da liana Chondrodendron platiphyllum. Apesar da similaridade quanto à estrutura anatômica geral do caule, existem caracteres que separam as trepadeiras herbáceas das lianas, tais como: o tipo de parênquima, morfologia dos cristais, o diâmetro e a distribuição dos elementos de tubos crivados e a transformação das iniciais, tanto fusiformes quanto radiais nas trepadeiras herbáceas. Fornece-se, ainda, alguns aspectos anatômicos do floema secundário no caule. Recomenda-se a padronização de estudos do lenho na família através do primeiro anel. Discute-se a presença de raio medular na família. Conclui-se que os caules das lianas são muito similares, portanto, a identificação das porções do lenho utilizadas em objetos comercializados somente é possível ao nível de família. / The pantropical family Menispermaceae includes several habits, like herbaceous vines, herbs, shrubs, and trees, showing cambial variant of successive type. The present study is an anatomical approach of stem and root of woody and herbaceous vine habits. In the present study, 31 specimens were investigated, sampling 10 genera and 14 species. Of those species, five are herbaceous vines, one is herb (Cissampelos ovalifolia) and one is shrub (Abuta grandifolia), and the rest are woody vines. Stems of woody vines and shrubs show successive cambia, not assigned to herbs and herbaceous vines. For the first time in the family, it is observed in the woody vine Abuta imene that the conjunctive tissue originates from the pericycle, and that the successive cambia, on its turn, originates from the conjunctive tissue. In the comparative analysis of secondary xylem in its several successive rings in the same stem, the wood produced by new vascular rings does not differ qualitatively from the original vascular ring, while there are differences in quantitative characters: diameter of vessel elements show significant increase in centreperiphery direction. The stem analysis between two habits of Abuta grandifolia (woody vine X shrub) shows that both have the same anatomical pattern. However, diameter of vessel elements is smaller in shrubs. Quantitative variation occurs between stem and root in herbaceous vine wood, and are related to diameter and length of vessel elements, which are larger in stems. Some data are described for the family for the first time: (1) The subterranean system of Disciphania hernandia is assigned as root tuber; (2) Splitting of ray by transformation of ray initials to fusiform initials in xylem and phloem; (3) Presence of successive cambia in woody vine root of Chondrodendron platiphyllum. Despite the anatomical general resemblance of stem, there are characters that distinguish herbaceous from woody vines, like: the kind of parenchyma, crystal morphology, diameter and distribution of sieve tube elements, and transformation of fusiform and ray initials in herbaceous vines. Additionally, some anatomical aspects of secondary phloem in stem are shown. The standardization of woody studies in the family considering the first ring is recommended. Discussions are made about the presence of medullary ray in the family. It is concluded that the stem of woody vines are very similar to each other, and thus, identification of woody portions used in commercialized objects is possible only at familial level.

A meta do trabalho é propor e testar a hipótese que a contagem de tráfego nas interseções da rede de transportes, ao invés de contagem de tráfego nos arcos, reduz o grau de indeterminação e torna mais precisa a matriz OD estimada pelo modelo sintético. Ademais, é proposto e detalhado um método de estimação da matriz OD através de médias sucessivas (MEMS). É apresentada a descrição matemática das propostas e o detalhamento dos experimentos elaborados para testá-las. Três métodos de estimação, QUEENSOD, TransCAD e MEMS, foram utilizados na verificação da hipótese. A inserção de \"arcos virtuais\" na rede de transportes constituiu um artifício que permitiu aos programas QUEENSOD e TransCAD realizarem a estimação utilizando fluxos observados nas interseções. A utilização de contagens de fluxo nas interseções propiciou à matriz OD estimada, melhorias que acarretaram sua aproximação com a matriz OD \"real\". O experimento mostrou que a matriz OD estimada ao considerar contagens de tráfego nas interseções apresenta melhor desempenho em comparação a matriz estimada ao considerar contagens nos arcos da rede de transportes. A matriz estimada gradativamente aproximou-se da \"real\" à medida que foi aumentada a quantidade de informação de fluxo e sua distribuição na rede. Assim, a hipótese formulada para este trabalho não pôde ser refutada. / The aim of this work is to propose and test the hypothesis that traffic counts collected at network intersections, instead of traffic counts collected at links, reduce indeterminacy and make more accurate the OD matrix estimated by the synthetic model. Furthermore, a method is proposed and described in detail to estimate the OD matrix based on successive averages (MEMS). The model formulation of the proposals and a description of the experiments are presented. Three estimation methods, QUEENSOD, TransCAD, and MEMS were used in the hypothesis verification. The use of \"virtual links\" in the network consists of an artifice that enable the QUEENSOD and TransCAD to estimate the OD matrix based on traffic counts at intersection. By using flow counts conducted at intersections, improvements could be made to the estimated OD matrix bringing it closer to \"real situations\". The experiments results show that the OD matrix estimation based on traffic counts collected on network intersection has a better performance in contrast to the estimation based on traffic counts collected on network links. The estimated matrix gradually becomes closer to \"real situations\" while the quantity of information flow and its distribution to the network is increased. Therefore, the formulated hypothesis for this work cannot be refuted.

Les communications sans fils sont devenues un outil fondamental pour les sociétés modernes. Les réseaux cellulaires sont le moyen préféré pour l’accès à Internet. L’augmentation de la capacité du réseau est étroitement liée au problème des interférences. Les réseaux coopératifs ont été largement étudiés dans les années récentes. Cette thèse porte sur deux techniques de coopération dans la voie descendante :La première partie étudie les effets de quantification et délais sur les informations de retour nécessaires pour la mise en opération des différentes techniques d’émission coordonnée, connues sous le nom de CoMP (Coordinated Multipoint Transmission). Cette technique qui promet des augmentations importantes sur la capacité du réseau en conditions idéales, or ses vrais résultats sous le feedback limité doivent être encore décrits de manière analytique. En particulier, pour les modes d’émission connus comme JT (Joint Transmission) et CBF (Coordinated Beamforming), des expressions analytiques ont été déduites pour calculer la capacité du réseau et la probabilité de succès de transmission.Finalement une nouvelle technique de coopération de réseau pour les récepteurs avancés du type SIC (Successive Interference Cancellation) est présentée. La condition mathématique qui garantit des gains de capacité grâce à l’utilisation des récepteurs SIC est obtenue. Pour en profiter, une méthode de coopération est nécessaire pour assurer une adaptation de lien adéquate pour que l’interférence soit décodable et le débit somme soit supérieur à celui atteint avec des récepteurs traditionnels. Cette technique montre des gains importants de capacité pour des utilisateurs en bordure de cellule. / Wireless communications have become a fundamental feature of any modern society. In particular, cellular networks are essential for societal welfare but the increasing demand for data traffic set enormous scientific challenges. Increasing the network capacity is closely related to the problem of interference mitigation. In this regard, network cooperation has been studied in recent years and several different techniques have been proposed. In the first part, different transmission techniques commonly referred to as Coordinated Multi-Point Transmission (CoMP), are studied under the effect of feedback quantization and delay, unequal pathloss and other-cell interference (OCI). An analytical framework is provided, which yields closed-form expressions to calculate the ergodic throughput and outage probabilities of Coordinated Beamforming (CBF) and Joint Transmission (JT). The results indicate the optimal configuration for a system using CoMP and provide guidelines and answers to key questions, such as how many transmitters to coordinate, how many antennas to use, how many users to serve, which SNR regime is more convenient, whether to apply CBF or prefer a more complex JT, etc. Second, a new coordination technique at the receiver side is proposed to obtain sum-rate gains by means of Successive Interference Cancellation (SIC). The conditions that guarantee network capacity gains by means of SIC at the receiver are provided. To take advantage of these conditions, network coordination is needed to adapt the rates to be properly decoded at the different users involved. This technique is named Cooperative SIC and is shown to provide significant throughput gains for cell-edge users.

O objetivo desta tese é investigar aspectos práticos que facilitem a aplicação da teoria de controle H1 não linear em projetos de sistemas de controle. A primeira contribuição deste trabalho é a proposta do uso de funções ponderação com dinâmica no projeto de controladores H1 não lineares. Essas funções são usadas no projeto de controladores H1 lineares para rejeição de perturbações, ruídos, atenuação de erro de rastreamento, dentre outras especificações. O maior obstáculo para aplicação prática da teoria de controle H1 não linear é a dificuldade para resolver simultaneamente as duas equações de Hamilton-Jacobi-Isaacs relacionadas ao problema de realimentação de estados e injeção da saída. Não há métodos sistematicos para resolver essas duas equações diferenciais parciais não lineares, equivalentes µas equações de Riccati da teoria de controle H1 linear. A segunda contribuição desta tese é um método para obter a injeção da saída transformando a equação de Hamilton-Jacobi-Isaacs em uma sequencia de equações diferenciais parciais lineares, que são resolvidas usando o método de Galerkin. Controladores H1 não lineares para um sistema de levitação magnética são obtidos usando o método clássico de expansão em série de Taylor e o método de proposto para comparação. / The purpose of this thesis is to investigate practical aspects to facilitate the ap- plication of nonlinear H1 theory in control systems design. Firstly, it is shown that dynamic weighting functions can be used to improve the performance and robustness of the nonlinear H1 controller such as in the design of H1 controllers for linear plants. The biggest bottleneck to the practical applications of nonlinear H1 control theory has been the di±culty in solving the Hamilton-Jacobi-Isaacs equations associated with the design of a state feedback and an output injection gain. There is no systematic numerical approach for solving this ¯rst order, nonlinear partial di®erential equations, which reduces to Riccati equations in the linear context. In this work, successive ap- proximation and Galerkin approximation methods are combined to derive an algorithm that produces an output injection gain. Design of nonlinear H1 controllers obtained by the well established Taylor approximation and by the proposed Galerkin approxi- mation method applied to a magnetic levitation system are presented for comparison purposes.

This thesis treats two essentially different subjects: V-cycle schemes are considered in Chapters 2-4, whereas the aggregation-based coarsening is analysed in Chapters 5-6. As a matter of paradox, these two multigrid ingredients, when combined together, can hardly lead to an optimal algorithm. Indeed, a V-cycle needs more accurate prolongations than the simple piecewise-constant one, associated to aggregation-based coarsening. On the other hand, aggregation-based approaches use almost exclusively piecewise constant prolongations, and therefore need more involved cycling strategies, K-cycle <a href=http://www3.interscience.wiley.com/journal/114286660/abstract?CRETRY=1&SRETRY=0>[Num.Lin.Alg.Appl., vol.15(2008), pp.473-487]</a> being an attractive alternative in this respect. <br> <br> Chapter 2 considers more precisely the well-known V-cycle convergence theories: the approximation property based analyses by Hackbusch (see [Multi-Grid Methods and Applications, 1985, pp.164-167]) and by McCormick [SIAM J.Numer.Anal., vol.22(1985), pp.634-643] and the successive subspace correction theory, as presented in [SIAM Review, vol.34(1992), pp.581-613] by Xu and in [Acta Numerica, vol.2(1993), pp.285-326.] by Yserentant. Under the constraint that the resulting upper bound on the convergence rate must be expressed with respect to parameters involving two successive levels at a time, these theories are compared. Unlike [Acta Numerica, vol.2(1993), pp.285-326.], where the comparison is performed on the basis of underlying assumptions in a particular PDE context, we compare directly the upper bounds. We show that these analyses are equivalent from the qualitative point of view. From the quantitative point of view, we show that the bound due to McCormick is always the best one. <br> <br> When the upper bound on the V-cycle convergence factor involves only two successive levels at a time, it can further be compared with the two-level convergence factor. Such comparison is performed in Chapter 3, showing that a nice two-grid convergence (at every level) leads to an optimal McCormick's bound (the best bound from the previous chapter) if and only if a norm of a given projector is bounded on every level. <br> <br> In Chapter 4 we consider the Fourier analysis setting for scalar PDEs and extend the comparison between two-grid and V-cycle multigrid methods to the smoothing factor. In particular, a two-sided bound involving the smoothing factor is obtained that defines an interval containing both the two-grid and V-cycle convergence rates. This interval is narrow when an additional parameter α is small enough, this latter being a simple function of Fourier components. <br> <br> Chapter 5 provides a theoretical framework for coarsening by aggregation. An upper bound is presented that relates the two-grid convergence factor with local quantities, each being related to a particular aggregate. The bound is shown to be asymptotically sharp for a large class of elliptic boundary value problems, including problems with anisotropic and discontinuous coefficients. <br> <br> In Chapter 6 we consider problems resulting from the discretization with edge finite elements of 3D curl-curl equation. The variables in such discretization are associated with edges. We investigate the performance of the Reitzinger and Schöberl algorithm [Num.Lin.Alg.Appl., vol.9(2002), pp.223-238], which uses aggregation techniques to construct the edge prolongation matrix. More precisely, we perform a Fourier analysis of the method in two-grid setting, showing its optimality. The analysis is supplemented with some numerical investigations.

The cyclic prefix (CP) is usually adopted in single carrier frequency domain equalization (SC-FDE) system to avoid inter-block interference (IBI) and inter-symbol interference (ISI) in multipath fading channels. In addition, the use of CP also converts the linear convolution between the transmitted signal and the channel into a circular convolution, leading to significant decrease in receiver equalization. However, the use of CP reduces the bandwidth efficiency. Therefore the SC-FDE system without CP is investigated in this thesis. A number of schemes have been proposed to improve the performance of systems without CP, where both IBI and ICI are dramatically increased. Unfortunately, most of the existing schemes have extremely high computational complexity and are difficult to realize. In this thesis, a novel low-complexity CP reconstruction (CPR) scheme is proposed for interference cancellation, where the successive interference cancellation (SIC) and QR decomposition (QRD) are adopted. In addition, the system performance is further improved by using the fact that the interferences of different symbols are not the same. Simulation experiments are conducted to verify the system performance of the proposed scheme. It is shown that the proposed scheme can effectively reduce the interference, while maintain a low computational complexity.

Commercialization of infrared (IR) vision is of vital importance for many applications, such as automobile and health care. The main obstacle in front of the further spread of this technology is the high price. The cost reduction is achieved by placing on-chip electronics and diminishing the camera size, where one of the important components is the analog-to-digital converter (ADC). This thesis reports the design of a successive approximation register (SAR) ADC for low-cost microbolometers and its test electronics. Imaging ADCs are optimized only for the specific application in order to achieve the lowest power, yet the highest performance. The successive approximation architecture is chosen, due to its low-power, small-area nature, high resolution potential, and the achievable speed, as the ADC needs to support a 160x120 imager at a frame rate of 25 frames/sec (fps). The resolution of the ADC is 14 bit at a sampling rate of 700 Ksample/sec (Ksps). The noise level is at the order of 1.3 LSBs. The true resolution of the ADC is set to be higher than the need of the current low-cost microbolometers, so that it is not the limiting factor for the overall noise specifications. The design is made using a 0.18&micro / m CMOS process, for easy porting of design to the next generation low-cost microbolometers. An optional dual buffer approach is used for improved linearity, a modified, resistive digital-to-analog converter (DAC) is used for enhanced digital correction, and a highly configurable digital controller is designed for on-silicon modification of the device. Also, a secondary 16-bit high performance ADC with the same topology is designed in this thesis. The target of the high resolution ADC is low speed sensors, such as temperature sensors or very small array sizes of infrared sensors. Both of the SAR ADCs are designed without switched capacitor circuits, the operation speed can be minimized as low as DC if an extremely low power operation is required. A compact test setup is designed and implemented for the ADC. It consists of a custom designed proximity card, an FPGA card, and a PC. The proximity card is designed for high resolution ADC testing and includes all analog utilities such as voltage references, voltage regulators, digital buffers, high resolution DACs for reference generation, voltage buffers, and a very high resolution &Delta / -&Sigma / DAC for input voltage generation. The proximity card is fabricated and supports automated tests, because many components surrounding the ADC are digitally controllable. The FPGA card is selected as a commercially available card with USB control. The full chip functionalities and performances of both ADCs are simulated. The complete layouts of both versions are finished and submitted to the foundry. The ADC prototypes consist of more than 7500 transistors including the digital circuitry. The power dissipation of the 16-bit ADC is around 10mW, where the 14-bit device consumes 30mW. Each of the dies is 1mm x 5mm, whereas the active circuits occupy around 0.5mm x 1.5mm silicon area. These chips are the first steps in METU for the realization of the digital-in digital-out low cost microbolometers and low cost sensors.