Intégration de mélangeurs optoélectroniques en technologie CMOS pour la télémétrie laser embarquée haute résolution

La mesure de distance et la détection d'objets sont devenues essentielles dans de nombreux domaines tels que l'automobile ou la robotique, les applications médicales, les procédés industriels et agricoles, les systèmes de surveillance et de sécurité, etc. Dans le but d'améliorer les performances des dispositifs de télémétrie laser en terme de bruit et de diaphonie, une technique hétérodyne par mélange optoélectronique doit être utilisée. Par ailleurs, l'aspect système embarqué nécessite une réduction de l'encombrement et de la consommation à performances égales. L'intégration de mélangeurs optoélectroniques en technologie CMOS apporte donc une solution optimale à cette approche grâce à ses multiples avantages (intégration du circuit d'instrumentation sur la même puce, modèles bien connus, coût raisonnable, performances élevées, ). Ainsi cette thèse traitera de l'étude de mélangeurs optoélectroniques en technologie CMOS pour la télémétrie embarquée haute résolution. Le premier chapitre de ce manuscrit présente les diverses technique de mesure de distance par télémétrie laser par et justifie le choix de la télémétrie laser par déphasage ainsi que le gain en performances lié à l'hétérodynage. Le second chapitre décrit les mélangeurs électriques et optoélectroniques ainsi que les propriétés nécessaires à leur réalisation. Quelques photodétecteurs y sont présentés au vu de la possibilité de les utiliser en mélangeurs optoélectroniques et d'une intégration potentielle en technologie CMOS. Les principales contraintes liées à l'intégration en technologie CMOS de photocapteurs utilisables en mélangeurs optoélectroniques, sont exposés dans la troisième partie. Les travaux de conception et d'optimisation des structures ainsi que les phases de simulations et de test y sont détaillés. Enfin, pour valider expérimentalement les études précédentes, le dernier chapitre présente la conception d'une chaîne de mesure multivoies pour une tête de photoréception CMOS matricée pour un télémètre laser embarqué haute résolution.Distance measurement and object detection has become essential in many fields such as automotive and robotics, medical applications, industrial processes and farming systems, surveillance and security, etc.. In order to improve the performance of laser ranging devices in terms of noise and crosstalk, an optoelectronic heterodyne technique of mixing should be used. Moreover, the aspect of embedded system requires a reduction in the size and power consumption for the same performance. The integration of optoelectronic mixers in CMOS technology will provide an optimal solution to this approach through its many advantages (integrated instrumentation circuit on the same chip, well-known models, reasonable cost, high performance, ...). Thus this thesis will focus on the study of optoelectronic mixers in CMOS technology for high resolution, embedded laser range finding systems. The first chapter of this thesis discusses the various technique of distance measurement by laser ranging and justifies the choice of phase shift technique and the gain in performance related to heterodyning. The second chapter describes the electrical and optoelectronic mixers and the properties needed to develop them. Some photodetectors are presented given the opportunity to use optoelectronic mixers and a potential integration with CMOS technology. The main constraints to the integration of CMOS photosensors used in optoelectronic mixers are set out in Part III. The work of design and optimization of structures and phases of simulations and testing are detailed. Finally, to experimentally confirm the earlier studies, the final chapter presents the design of a measuring head for a multichannel photoreceptor CMOS for a high resolution laser range finder.TOULOUSE-INP (315552154) / SudocSudocFranceF

Graphene in silicon photovoltaic cells

Graphene is an allotrope of carbon. Its structure is one-atom-thick planar sheets of carbon atoms that are densely packed in a honeycomb crystal lattice [1]. The richness of optical and electronic properties of graphene attracts enormous interest. Its true potential seems to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited. The optical absorption of graphene layers is proportional to the number of layers, each absorbing A=1-T=πα=2.3% over the visible spectrum [2].The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Current photovoltaic (PV) technology is dominated by Si cells, with an energy conversion coefficient up to 25% [3]. Such an inorganic PV consists in a current transparent conductor (TC) replacing one of the electrodes of a PIN photodiode. The standard material used so far for these electrodes is indium-tinoxide, or ITO. But indium is expensive and relatively rare, so the search has been on for a suitable replacement. A possible substitute made from inexpensive and ubiquitous carbon is graphene. Being only constituted of carbon, it will become cheap and easily recyclable. But at the moment, the major difficulty consists in its fabrication and/or transfer. Our project consists in synthetizing graphene by CVD (Chemical Vapor Deposition) on Cu and in transferring the obtained layer on silicon PV cells, and then in testing their energy conversion efficiency

Intégration de réseaux de neurones pour la télémétrie laser

Un réseau de neurones est une architecture paramétrable composée de plusieurs modules appelés neurones. Ils peuvent être utilisés pour compenser des variations non souhaitées de certains phénomènes physiques ou pour effectuer des tâches de discrimination. Un réseau de neurones a été intégré en technologie CMOS basse tension pour être implanté au sein d'un télémètre laser par déphasage. Deux études ont été menées en parallèle. La première consiste à lever l'indétermination sur la mesure de distance déduite de la mesure de déphasage. La seconde étude permet la classification de différents types de surfaces à partir de deux signaux issus du télémètre.TOULOUSE-ENSEEIHT (315552331) / SudocSudocFranceF

An Analog CMOS Voltage-Controlled Phase-Shifter With A 100° Tuning Range For Telecommunication Baseband Signal Processing

International audienceIn order to correct phase non-linearities due to High Power Amplifiers (HPA) operating near saturation in telecommu-nication transceivers, a voltage-controlled phase-shifter based on Differential Difference Current Conveyors (DDCC) and a tunable resistor were developed. In order to suit a large variety of HPAs with broad phase non-linearities, the circuit's tuning capability has even been optimized up to an unprecedented 100 • while maintaining a good linearity (THD<-30 dB) and a gain close to 0 dB at 50 MHz. Designed in a 3.3 V 0.35 µm CMOS technology, the circuit current consumption ranges from 3.5 mA to 4.5 mA for a 50 MHz bandwidth, depending on the tuning range to be achieved. This paper describes the general architecture of the phase shifter as well as the inner structure of each implemented function and presents simulation results of the whole circuit

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Doctora

Radiation hardened bootstrapped switch in 0.18μm CMOS process

International audienceThis paper presents a low-voltage bootstrapped switch that adopts a new technique to achieve its radiation hardening by design (RHBD). In order to improve the performances of CMOS switches used for switched-capacitor (SC) circuits, such as in sample-and-hold circuits or in pipeline analog-to-digital SC amplification stage, bootstrapped techniques are necessary but should not be directly applied for circuits operating in a radiative environment. The critical nodes of the conventional bootstrapped switch will be highlighted and the devised method to size correctly certain MOS transistors within the bootstrapped circuit will be shown. To verify the proposed methodology, a bootstrapped switch is designed in a HV 0.18μm CMOS technology and its performances are compared to a conventional bootstrapped architecture

Radiation Hardened by Design Pipeline Analog-to-Digital Converter Blocks in CMOS HV 0.18µm Technology

International audienceIn this paper, we present an approach to achieve radiation hardening by design (RHBD) for the main three blocks involved in pipelined Analog-to-Digital converters (ADCs): switches, comparators and residue amplifiers. A method to design bootstrapped switches has been devised to avoid voltage overshoots. Dual path with auto-zero techniques have been implemented for the comparators to be less prone to single effect upset (SEU). Finally, predictive switched capacitor techniques have been used for the residue amplifier in order to benefit from a simpler low-power amplifier architecture. To verify the proposed methodology, these blocks were implemented in an HV 0.18μm CMOS technology

Innovative Technique for HPA Characteristics Extraction and Accurate Predistorsion Function Modeling

International audienceIn telecommunications, the combination of modulations with non-constant envelope together with nonlinearities leads to strong distortions of the transmitted signals. The linearization purpose is to assure an optimal link transmission quality. In this article, an innovative method to extract linearization characteristics is presented. This technique, using directly experimental data rather than a High Power Amplifier (HPA) modeling, is fast and allows an important linearization accuracy and computational workload improvement compared to classical modeling techniques. It is then applied to determine the ideal linearizer AM/AM and AM/PM transfer characteristics to exploit three real HPA to their fullest

An amperometric silicon-based biosensor for d-lactate

International audienceA miniaturised biosensor for d-lactate has been fabricated on silicon wafer. Microsystems technologies led to enhanced efficiency in terms of sample size and reagent consumption while equally allowing mass production. The biosensor is based on the association of an enzymatic solution including diaphorase and d-lactate dehydrogenase confined in the microstructure by a membrane and two weakly polarised gold microelectrodes. Various electrochemical pretreatments of the gold surface are performed to increase the device's sensitivity. Depending on the geometry involved, the proposed biosensor features a response time ranging from 2 to 5 min, a sensitivity of 2 or 8 μA mM−1 cm−2 and a linearity range from 5×10−3 to 1.5 mmol l−1. Its lifetime is 3 weeks with 10 assays/day

Design of a Silicon Based Amperometric Microbiosensor Involving NAD-Dependent Dehydrogenase

An electrochemical microbiosensor involving NAD-dependent dehydrogenase has been designed and developed using silicon technology. The sensor is based on a weakly polarized two-gold microelectrode system without any reference electrode. The process allowed mass production of miniaturized devices. An enzymatic solution including diaphorase and NAD-dependent dehydrogenase was confined in the microstructure by means of a semi-permeable membrane. The biocompatibility of the various materials was verified and the gold electrodes were electrochemically characterized. The assay of D-lactic acid was taken as an example using D-lactate dehydrogenase. The sensitivity and detection limit of the microbiosensor were 8 μA mM–1 cm–2 and 0.01 mM respectively. Its lifetime was 3 weeks