A l'heure où la demande en quantité d'informations et le nombre d'utilisateurs explosent, toujours avec des limitations en allocation en fréquence et bande passante, les systèmes de télécommunication tendent à optimiser la gestion de leur capacité en s'orientant vers des systèmes reconfigurables. Dans le cas des filtres d'OMUX, apporter de l'accordabilité en conservant d'excellentes performances électriques, thermiques et mécaniques soulève de nombreuses difficultés.Nous avons dans un premier temps démontré la faisabilité sur un filtre à saut de canal à bande passante constante par le biais d'une cavité métallique chargée par un perturbateur en alumine en mouvement de rotation. Ensuite, nous avons proposé des solutions pour avoir un contrôle de la fréquence et de la bande passante en se basant sur la translation de matériaux diélectriques. Les facteurs de qualité mis en jeu sont de l'ordre de la dizaine de milliers. Enfin nous avons tiré profit de l'évolution des technologies d'impression plastique 3D pour valider différents concepts de filtres accordables. / At a time when the amount of information and the number of users go through the roof in telecommunication market, the telecommunication systems tend to improve the management of their capacity by moving toward reconfigurable RF devices. However frequency and bandwidth allocated are still restricted. Regarding tunable OMUX filters, the actuation systems generally degrade the overall performances of the device and raise questions in terms of mechanic and thermic.We first demonstrated the feasability of a two state filter with constant narrowband, using a dielectric material (alumina) in rotation inside a metallic housing. Then, we suggested solutions to control both frequency and bandwidth with the translation of a ceramics. We deal with quality factor in the range of ten of thousands for these applications. Eventually, we validated some principle for tunable filters thanks to the efficiency of 3D plastic printer.

This master thesis deals with the problematics of CT filters and focuses on Gm – C filter. Three linearisation techniques are listed and compared in terms of linear input range, distortion and retuning. In the practical part – second - order low – pass filter is designed and its tuning capabilities are examined.

An RF switch in substrate integrated waveguide (SIW) technology for X-band is designed and demonstrated. Design is based on embedding shunt pin diodes of the switch in an evanescent mode waveguide filter. At reverse bias, pin diodes formed a part of filter&#039 / s capacitances. Thus switch also functions as a filter when it is in &ldquo / on&rdquo / state. At forward bias of diodes, capacitances of the filter are short circuited to obtain a good isolation. The same circuit structure is used to design a tunable filter and an RF power limiter which also functions as a filter. Several RF functions usually used in RF frontends (power limiting, filtering, switching) are combined in a single circuit which helps miniaturization of the frontend. The circuit can be produced with standard PCB and chip&amp / wire technology. The circuits developed have comparable performances with microstrip counterparts and they are advantageous to use in microwave systems using SIW as the basic transmission medium and need filtering functionality.

For the new generation wireless communication systems, there is an increasing demand for devices that covers more than one frequency band. This results in a need for wide-band tunable front-ends. The main objective of this study is to use dual band filters in the design of a multi-band front-end. A wide-band low noise amplifier is also required. To accomplish this project, a fixed frequency bandstop filter, a tunable dual-band filter and a wide-band LNA are designed and implemented successfully. The predefined specifications of this front-end include gain, gain flatness, spurious signal rejection, frequency tuning range, noise figure and linearity. Total power dissipation and number of elements are also taken into consideration. Test results of the manufactured front-end are compared with the results of existing single band front-ends. In order to design a good tunable wide-band filter, just tuning its center frequency will not be enough. The noise figure of this dual-band filter will be proportional to its insertion loss if it will be used as a pre-selection filter in front of a LNA. Hence its insertion loss will affect the overall noise figure of the system. If it will be used after the LNA, its linearity will be more important. When a bandpass filter is tuned over wide range of frequencies, its bandwidth varies significantly which leads to a degradation in rejection of the spurious signals. Therefore, there must be a simultaneous control of center frequency, bandwidth and insertion loss while providing enough linearity. In order to accomplish this mission, a filter that has two passbands is designed and implemented. The first passband is tunable between 136MHz and 174MHz while the second one is tunable between 380MHz and 470MHz. Also, the low noise amplifier works properly between 136MHz and 470MHz. As a result, a front-end that covers two bands is obtained.

Cette thèse de doctorat traite de la réalisation et la caractérisation métrologique d’un pyromètre à filtre accordable acousto-optique (AOTF). La première partie expérimentale de ce travail a été consacrée à l’étude du fonctionnement et de la caractérisation du filtre AOTF, la seconde, a été dédiée au développement et à l’optimisation du pyromètre AOTF.Contrairement aux pyromètres habituels dont la sélection spectrale est obtenue par un filtre interférentiel, le pyromètre accordable développé dans ce document utilise un filtre acousto-optique adapté à un étalonnage par laser. La longueur d’onde optique de mesure est imposée par la fréquence de l’onde radiofréquence appliquée au filtre acousto-optique, qui ne requiert aucun mouvement mécanique.En contrepartie, le spectre optique diffracté par ce type de filtres, présente d’importants lobes secondaires de diffraction qui dégradent le taux de réjection hors bande du pyromètre. Grace à un montage en double passage dans une configuration optique en œil de chat, les lobes secondaires de diffraction ont été fortement atténués. Le taux de diffusion optique du pyromètre est de l’ordre de 10-5 en valeur relative.La reproductibilité de sa sensibilité spectrale en longueur d’onde est de 0,01 nm et 0,1 % en amplitude sur une semaine. Ces caractéristiques, comparables à celles des meilleurs monochromateurs, permettent l'utilisation du pyromètre AOTF pour des applications métrologiques au meilleur niveau d’exactitude. L'instrument est accordable en longueur d'onde sur un domaine étendu, compris entre 600 nm et 950 nm. Il est également transportable car sa masse est inférieure à 20 kg et sa longueur inférieure à 1 m. Les performances et la caractérisation métrologique du pyromètre ont été validées par la mesure de la température thermodynamique du point du cuivre, en accord avec celle donnée dans l'EIT-90. / This PhD Thesis presents the work that has been done to design and build, along with the evaluation of the radiometric performance, of a radiation pyrometer based on acousto-optic tunable filter (AOTF). Part of this work has been given to the characterization of the acousto-optic tunable filter (AOTF); however, the other part has been dedicated to the development and the optimization of the radiation pyrometer.Unlike conventional pyrometers whose spectral selection is obtained an interference filters, the AOTF that has been used in this work enables direct calibration of the radiation pyrometer using laser sources without any interference effects. This in turns allows direct calibration of the pyrometer against the cryogenic radiometer or through trap detectors with lower uncertainty levels. The spectral range selected by the AOTF is adjusted by changing the frequency applied to the filter without any mechanical movement, which is an advantage compared to grating-based systems.One of the main limitations in using AOTF is the existence of diffraction lobes which appear beyond the in-band spectral range. These lobes result in significant deterioration in the blocking capabilities of the filter, and thus an increased out-of-band signal levels are obtained. However this has been solved by using a double-pass optical configuration, which has reduced these diffraction lobes and kept them within insignificant levels. The resultant out-of-band signal levels have been found within 10-5 of the in-band signal. The reproducibility of wavelength calibration is within 0.01 nm, yet with 0.1 % reproducibility in the amplitude of the in-band signal over a course of one week. The stability of wavelength is comparable to that found in high quality monochromators. This in turns allows the use of our pyrometer in metrological applications that require high level of accuracy. The instrument spectral coverage can be tuned over a wide spectral range, between 600 nm and 950 nm. The pyrometer is also transportable as its mass is less than 20 kg and with dimensions of 90 L x 20 H x 30 W cm. The performance and metrological characterization of the pyrometer have been validated by measuring the thermodynamic temperature of the freezing point of the copper, which was in a very good agreement with that value defined by the International Temperature Scale (ITS-90).

Optofluidics is a relatively new and exciting field that includes the integration of optical waveguides into microfluidic platforms. The purpose of this field of study is to miniaturize previously developed optical systems used for biological and chemical analysis with the end goal of placing bench-top optics into microscopic packages. Mundane optical alignment and sample manipulation procedures would then be intrinsic to the platform and allow measurements to be completed quickly and with reduced human interaction. Biosensors based on AntiResonant Reflecting Optical Waveguides (ARROWs) consist of hollow-core waveguides used for fluid sample manipulation and analysis, as well as solid-core waveguides used in interfacing external components located at the chip edges. Hollow-core ARROWs are particularly useful for their ability to provide specifically tailored analyte volumes that are easily configurable depending upon the target experiment. Adaptations of standard planar microfabrication methods allow for complex integrated ARROW designs. Integrated spectral filtering with high rejection can be implemented on-chip, removing the need for additional off-chip components and increasing device sensitivity. Additional techniques to increase device sensitivity and utility, such as hybrid ARROW platforms and optical manipulation of samples, are also explored.

<div>The allocated frequency bands for the incoming fifth generation (5G) wireless communication technologies spread broadly from sub 6 GHz to K and potentially W bands. The evolution of the future generations toward higher frequency bands will continue and presents significant challenges in terms of excessive system complexity, production and maintenance costs. Reconfigurable radio architecture with frequency-tunable components is one of the most feasible and cost-effective solutions to meet such challenges. Among these technologies, evanescent-mode (EVA) cavity tunable resonator have demonstrated many of the needed features such as wide tunability, low loss and high linearity. Such a technology typically employs a movable membrane that controls the resonant frequency of a post-loaded cavity. </div><div><br></div><div>The first part of this work focuses on advancing such technology into the mm-wave frequency bands and beyond. Manufacturing tolerance and tuner performance are the two main limiting factors addressed here. This work develops a cost-effective micro-fabrication and package assembly flow which addresses the manufacturing related limitations. On the other hand, introducing micro-corrugated diaphragms and gold-vanadium co-sputtered thin film deposition technology, significantly reduces (4 times) the tuning voltage and enhances tuning stability (7 times). We demonstrate a tunable two-pole band-pass filter (BPF) prototype as the first EVA cavity tunable filter operating in the K-Ka band. </div><div><br></div><div>The second part of this work extensively discusses an optimal RF design flow based on the developed manufacturing technology. It considers all technology constrains and allows the actualization of a high Q transfer function with minimum bandwidth variation within an octave tuning range. Moreover, a new fully passive input/output feeding mechanism that facilitates impedance matching over the entire tuning range is presented. The devised RF methodology is validated through the design and testing of a two-resonator BPF. Measurements demonstrate a tuning range between 20-40 GHz, relative bandwidth of 1.9%-4.7%, and impedance matching over the entire tuning range which is upto 2 times better than previously reported state-of-the-art MEMS tunable filters of this type.</div><div><br></div><div>The third part of this work further advances the technology by proposing the first MEMS-based low-power bi-directional EVA tuning approach that employs both the main bias circuitry as well as a new corrective biasing technique that counteracts viscoelastic memory effects. The two key enabling technologies are extensively discussed: a) a new metal-oxide-metal (MOM) sealed cavity that maintains high quality without requiring complicated metal bonding; and b) a new electrostatic bi-directional MEMS tuner that implements the needed frequency tuning without lowering the resonator quality factor. </div><div><br></div><div>Furthermore, we explore important design and fabrication trade-offs regarding sensitivity to non-ideal effects (residual stress, fabrication imperfections). Measurement of the new prototype bi-directional design, prove that this technology readily corrects residual post-bias displacement of 0.1 um that shifts the frequency by over 1 GHz with less than 2.5 V. It takes over 100 seconds to recover this error in the uni-directional case. This correction does not adversely affect the filter performance.</div>

L’imagerie hyperspectrale, qui consiste à acquérir l'image d'une scène dans un grand nombre de bandes spectrales, permet de détecter des cibles là où l'imagerie couleur classique ne permettrait pas de conclure. Les imageurs hyperspectraux à acquisition séquentielle sont inadaptés aux applications de détection en temps réel. Dans cette thèse, nous proposons d’utiliser un imageur multispectral snapshot, capable d’acquérir simultanément un nombre réduit de bandes spectrales sur un unique détecteur matriciel. Le capteur offrant un nombre de pixels limité, il est nécessaire de réaliser un compromis en choisissant soigneusement le nombre et les profils spectraux des filtres de l'imageur afin d’optimiser la performance de détection. Dans cet objectif, nous avons développé une méthode de sélection de bandes qui peut être utilisée dans la conception d’imageurs multispectraux basés sur une matrice de filtres fixes ou accordables. Nous montrons, à partir d'images hyperspectrales issues de différentes campagnes de mesure, que la sélection des bandes spectrales à acquérir peut conduire à des imageurs multispectraux capables de détecter des cibles ou des anomalies avec une efficacité de détection proche de celle obtenue avec une résolution hyperspectrale. Nous développons conjointement un démonstrateur constitué d'une matrice de 4 filtres de Fabry-Perot accordables électroniquement en vue de son implantation sur un imageur multispectral snapshot agile. Ces filtres sont développés en technologie MOEMS (microsystèmes opto-électro-mécaniques) en partenariat avec l'Institut d'Electronique Fondamentale. Nous présentons le dimensionnement optique du dispositif ainsi qu'une étude de tolérancement qui a permis de valider sa faisabilité. / Hyperspectral imaging, which consists in acquiring the image of a scene in a large number of spectral bands, can be used to detect targets that are not visible using conventional color imaging. Hyperspectral imagers based on sequential acquisition are unsuitable for real-time detection applications. In this thesis, we propose to use a snapshot multispectral imager able to acquire simultaneously a small number of spectral bands on a single image sensor. As the sensor offers a limited number of pixels, it is necessary to achieve a trade-off by carefully choosing the number and the spectral profiles of the imager’s filters in order to optimize the detection performance. For this purpose, we developed a band selection method that can be used to design multispectral imagers based on arrays of fixed or tunable filters. We use real hyperspectral images to show that the selection of spectral bands can lead to multispectral imagers able to compete against hyperspectral imagers for target detection and anomaly detection applications while allowing snapshot acquisition and real-time detection. We jointly develop an adaptive snapshot multispectral imager based on an array of 4 electronically tunable Fabry-Perot filters. The filters are developed in MOEMS technology (Micro-Opto-Electro-Mechanical Systems) in partnership with the Institut d'Electronique Fondamentale. We present the optical design of the device and a study of tolerancing which has validated its feasibility.

Le but de ce travail était de développer des filtres passe-bande RF dans la technologie de PCB, avec trois objectifs principaux. Le premier objectif était de développer des formules de synthèse tosimplify la procédure de conception du filtre. Le deuxième était de parvenir à un rejet wideout bande sans modifier les caractéristiques de la bande de filtrage. Le troisième objectif est de contrôler la fréquence centrale du filtre en utilisant diode varicap. / The purpose of this work was to develop RF bandpass filters in PCB technology,with three main objectives. The first objective was to develop synthesis formulas tosimplify the design procedure of the filter. The second was to achieve wideout-of-band rejection without modifying the in-band filtering characteristics. Thethird objective was to control the center frequency of the filter by using varactordiode.The bandpass filter topology treated in this thesis is based on Stub-LoadedResonators (SLR). The main features of this filter topology were treated. Equivalentcircuits based on J-inverters and susceptance parameters were derived. Based onthese equivalent circuits, synthesis formulas were developed. Simulations werepresented to validate the synthesis theory. For a proof-of-concept, third orderstripline bandpass filters were designed and fabricated based on this synthesis.Analysis technique using odd- and even- mode was achieved on the SLR. Thusresonance odd- and even-mode conditions were derived. These conditions aim toeasily control the first spurious frequency. Moreover, to go further in improving theout-of-band rejection a new technique, called “U corner structure”, was developedand design rules were derived. Based on these design rules an extended out-of-bandrejection was achieved without any modification in the passband and by maintainingthe compactness of the filter. A first spurious frequency was localized at up to ninetimes the working frequency in the case of the Parallel-coupled Stub-Loadedresonator (PC-SLR) filter. Also, by applying this technique into the classicalparallel-coupled filter the first and second spurious frequencies were rejected. Toaddress the issue of tunable filters, the SLRs were correctly loaded by variablecapacitors (varactor diode). The center frequency of the PC-SLR filter was easilycontrolled by maintaining a large out-of-band rejection.

De nouveaux besoins dans le domaine des télécommunications par satellite ont amené les industriels du secteur à se pencher sur l’optimisation des ressources en créant des systèmes reconfigurables, capables d’adapter leur fonctionnement fréquentiel en cours de mission. Cette thèse s’intéresse plus particulièrement aux multiplexeurs et à la manière de les rendre agiles à travers les filtres qui les composent ainsi qu’une adaptation de leur architecture.Dans un premier temps, le présent manuscrit dresse l’état de l’art des dispositifs accordables réalisés par les équipes de recherche du monde entier, avant de proposer des solutions mettant en œuvre une topologie de multiplexage à coupleurs hybrides. Dans un second temps, des études sont présentées portant sur une pluralité de concepts de cavités ou d’éléments de couplage accordables. Certains de ces concepts sont ensuite sélectionnés et assemblés afin de former des fonctions de filtrage et de multiplexage accordables. La dernière partie présente ainsi deux multiplexeurs accordables, l’un permettant une reconfiguration en bande étroite, l’autre en bande large, le premier ayant donné lieu à une réalisation expérimentale. / New needs in the field of satellite telecommunications have led manufacturers in the sector to focus on optimizing resources by creating reconfigurable systems able to adapt their operating frequencyplan during the mission. This thesis focuses on multiplexers and how to make them agile through their architecture and the filters that compose them.This manuscript starts by realizing the state of the art oftunable filtering devices through analysis of contributions made by research teams around the world. Based on this state of art,solutions to the problematic are proposed using a hybrid coupler multiplexing topology. Then studies are presented on various tunable cavities or coupling elements concepts. Some of these concepts have been selected and assembled to form tunable filtering and multiplexing functions. The last part thus presents two tunable multiplexers, allowing narrowband or broadband reconfiguration. An experimental realization has also been conducted on the narrowband version.