Low Voltage Totally Free Flexible RF MEMS Switch With Anti-Stiction System

This paper concerns a new design of RF MEMS switch combined with an innovative process which enable low actuation voltage (<5V) and avoid stiction. First, the structure described with principal design issues, the corresponding anti-stiction system is presented and FEM simulations are done. Then, a short description of the process flow based on two non polymer sacrificial layers. Finally, RF measurements are presented and preliminary experimental protocol and results of anti-stiction validation is detailed. Resulting RF performances are -30dB of isolation and -0.45dB of insertion loss at 10 GHz.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

A New Four States High Deflection Low Actuation Voltage Electrostatic Mems Switch for RF Applications

This paper presents a new electrostatic MEMS (MicroElectroMechanical System) based on a single high reliability totally free flexible membrane. Using four electrodes, this structure enables four states which allowed large deflections (4µm) with low actuation voltage (7,5V). This design presents also a good contact force and improve the restoring force of the structure. As an example of application, a Single Pole Double Throw (SPDT) for 24GHz applications, based on this design, has been simulated

Conception, réalisation et caractérisation de composants de puissance hyperfréquence de la filière nitrure de gallium

Ce travail porte sur la conception, la fabrication et la caractérisation de transistors HEMTs de la filière AIGaN/GaN. Le but est d'optimiser la technologie du composant afin d'exploiter les potentialités en termes de puissance hyperfréquence offertes par la filière nitrure. Le premier chapitre passe en revue les différentes filières de transistors de puissance, puis les propriétés physiques du GaN et les techniques d'élaboration du matériau sur différents substrats. Nous discutons des effets liés à l' autoéchauffement ou aux pièges, qu'il convient de minimiser pour améliorer les performances des transistors HEMTs. Enfin, un état de l'art des performances actuelles est présenté. Le deuxième chapitre présente les étapes technologiques du composant ainsi que leurs optimisations nécessaires à l'amélioration des performances des transistors, telles que les contacts ohmiques et les traitements de surface.La technologie de grille nitrure a été développée pour la filière GaN. Cette technologie a permis de fabriquer des grilles de faibles longueurs avec des topologies variables telles que la grille r, le tout avec un bon rendement de fabrication et une autopassivation. Elle a permis également de réaliser un fossé de grille en utilisant le digital etching . Cette technologie a donné la possibilité de fabriquer des composants ayant une longueur de grille de 70 nm tout en conservant un rapport d'aspect favorable. Le troisième et dernier chapitre traite de la caractérisation des transistors HEMTS en régime statique ou d'impulsions, en hyperfréquence et en puissance. Les résultats convaincants montrent tout l'intérêt de la technologie de grille nitrure associé au recess de grille. Ainsi, des composants utilisant ce procédé, ont permis d'obtenir l'état de l'art sur substrat Si(100) avec une puissance maximum, de sortie de 1 W/mm à 2,15 GHz, un gain en puissance de 24 dB et un rendement de 17%.LILLE1-BU (590092102) / SudocSudocFranceF

miREM: an expectation-maximization approach for prioritizing miRNAs associated with gene-set

Abstract Background The knowledge of miRNAs regulating the expression of sets of mRNAs has led to novel insights into numerous and diverse cellular mechanisms. While a single miRNA may regulate many genes, one gene can be regulated by multiple miRNAs, presenting a complex relationship to model for accurate predictions. Results Here, we introduce miREM, a program that couples an expectation-maximization (EM) algorithm to the common approach of hypergeometric probability (HP), which improves the prediction and prioritization of miRNAs from gene-sets of interest. miREM has been made available through a web-server (https://bioinfo-csi.nus.edu.sg/mirem2/) that can be accessed through an intuitive graphical user interface. The program incorporates a large compendium of human/mouse miRNA-target prediction databases to enhance prediction. Users may upload their genes of interest in various formats as an input and select whether to consider non-conserved miRNAs, amongst filtering options. Results are reported in a rich graphical interface that allows users to: (i) prioritize predicted miRNAs through a scatterplot of HP p-values and EM scores; (ii) visualize the predicted miRNAs and corresponding genes through a heatmap; and (iii) identify and filter homologous or duplicated predictions by clustering them according to their seed sequences. Conclusion We tested miREM using RNAseq datasets from two single “spiked” knock-in miRNA experiments and two double knock-out miRNA experiments. miREM predicted these manipulated miRNAs as having high EM scores from the gene set signatures (i.e. top predictions for single knock-in and double knock-out miRNA experiments). Finally, we have demonstrated that miREM predictions are either similar or better than results provided by existing programs

Characterization of VIM-4 Producing Clinical Pseudomonas aeruginosa Isolates from Western Algeria: Sequence Type and Class 1 Integron Description

International audienceObjectives: Pseudomonas aeruginosa occupies a central position in nosocomial infections and remains a significant cause of morbidity and mortality. The aim of this study was to characterize carbapenem resistance mechanisms in P. aeruginosa isolates from clinical specimens collected at the University Hospital of Oran, western Algeria. Materials and Methods: The identification of 214 nonduplicated P. aeruginosa isolates (collected from January to December 2016) was confirmed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Thirteen antibiotics were tested using the disc diffusion method. Carbapenemase-encoding genes were detected with the GeneXpert system and multiplex polymerase chain reaction (PCR). Clonal relatedness was determined using multilocus sequence typing (MLST) and the seven housekeeping genes were further used for phylogenetic analysis of imipenem-resistant P. aeruginosa using concatenated gene fragments. The flanking regions of the blaVIM-4 gene were analyzed by whole-genome sequencing. Results: Eleven isolates (5.39%) were resistant to carbapenems. PCR amplification and sequencing showed that six of these isolates (2.94%) harbored the blaVIM-4 gene that was carried on a novel class 1 integron. MLST analysis assigned the tested isolates to seven different sequence types (STs), of which two were new (ST3349 and ST3350) and five were previously described (ST244, ST499, ST709, ST809, and ST1239). Conclusion: In this study, we reported P. aeruginosa isolates producing VIM-4 in an Algerian hospital. The blaVIM-4 is harbored in class 1 integron with a new arrangement of genes cassettes