Comparison of De-embedding Methods for Long Millimeter and Sub-Millimeter-Wave Integrated Circuits

National audienceThis paper compares several de-embedding methods over millimeter and sub-millimeter wave frequen-cies in integrated technology. These methods are compared for S-CPW transmission lines considered as device under test. From these comparisons we propose an effective way to de-embed transmission lines. A method called "Half-Thru de-embedding method" is especially discussed. The SCPW transmission line model and results are obtained from Ansys HFSS Simulations in BiCMOS 55-nm integrat-ed technology

Design and characterization of a signal insulation coreless transformer integrated in a CMOS gate driver chip

International audienceWith the development of multi-level, multiphase or network converters requiring the implementation of numerous distinct power transistor gate drivers, the control signal insulation is becoming more and more important in power converters. This paper presents an isolation technique based on a coreless transformer integrated in a CMOS silicon die together with the gate driver and other required functions. The associated demodulation circuit will also be presented, as the control signal must be modulated at a high frequency through the coreless transformer. The chosen design methodology will be explained and experimental results will be shown in order to validate the functionality

Transfert isolé des signaux de commande dans le contexte de l'intégration pour les composants actifs d'électronique de puissance

Cet article présente plusieurs solutions originales afin de réaliser un transfert isolé des ordres de commutation pour les semiconducteurs de puissance. Sous la contrainte de l'intégration aussi bien monolithique qu'hétérogène, trois solutions sont présentées de façons théoriques et expérimentales. Le premier mode de réalisation intégrée de l'isolation galvanique est une solution optique intégrée au composant de puissance et/ou au sein de son circuit de commande de type CMOS. Les performances statiques et dynamiques des récepteurs optiques sont tout à fait compatibles avec l'application. Enfin, plusieurs transformateurs sans noyau magnétique sont conçus, analysés et caractérisés via une réalisation CMOS, en prenant un soin particulier aux couplages hautes fréquences et éléments parasites. Ce circuit de transmission électromagnétique des ordres est intégré avec plusieurs fonctions de pilotages et le bon fonctionnement de l'ensemble du driver est démontré aussi bien pour les composants Haute Tension High Side que Low Side

Etude et réalisation de réseaux d'adaptation d'impédances accordables linéaires et non linéaires, sur PCB et silicium CMOS, pour des applications en radiofréquences

L objectif de ce travail est d aborder la conception de réseaux d adaptation d impédance accordable (RAA) dans deux contextes bien distincts en radiofréquences : le RAA en faible signal et le RAA en fort signal.Concernant les aspects faible signal, des critères de performance de RAA ont été établis et étudiés. Une nouvelle expression générale de l efficacité d un RAA a été développée. Elle permet de prédire le rendement d un RAA à partir des facteurs de qualité des composants dont on dispose dans une technologie donnée et du rapport de transformation à réaliser. Des abaques de couverture d impédances en fonction des pertes d insertion ont été calculés. Ils mettent en évidence les régions de couverture où le RAA apporte une amélioration à la performance du système, pour diverses topologies de RAA.Un démonstrateur sur PCB a été réalisé. Il est constitué de deux RAA, qui assurent l adaptation simultanée d un amplificateur de puissance sur une large plage d impédances, comprises dans un cercle de l abaque de Smith d équation VSWR < 5 :1. La zone de couverture a été mesurée et présentée en fonction des pertes d insertion, qui mettent en évidence les régions où les RAA contribuent à l amélioration de la performance de l amplificateur et celles où les pertes d insertion du RAA n arrivent pas à compenser le gain du à la réduction des coefficients de réflexion.Dans une seconde partie, la conception de RAA en fort signal a été traitée. L objectif a été de présenter à la sortie d un amplificateur de puissance les impédances qui optimisent son efficacité pour chaque puissance de travail. Un démonstrateur en technologie CMOS SOI 130 nm a été conçu et simulé. Il consiste en un amplificateur de puissance pour le standard WCDMA, fonctionnant à 900 MHz, et un RA accordable par des varactors MOS, capable de générer les impédances optimales correspondant à des puissances de sortie comprises entre 20 et 30 dBm. Les résultats ont mis en évidence le bénéfice apporté par l insertion d un RA accordable par rapport à un RA fixe.The aim of this research was the design of tunable matching networks, in two different contexts: the TMN at low and high signals.Performance criteria of TMN were studied. A general expression has been developed that estimates the TMN efficiency in function of the quality factor of the components used. The impedance coverage of different RAA topologies was plotted in function of the insertion losses.For the small signal, we designed a prototype in PCB, composed by two TMN, which ensure the simultaneous matching of a power amplifier in a wide range of impedances, included in a circle of the Smith chart VSWR < 5: 1. The coverage area was measured and presented in function of the insertion losses, emphasizing the areas where the TMN contribute to improve the amplifier performance and those where insertion losses of the TMN are not able to compensate gain with the reduction of the reflection coefficients.Subsequently, we discussed the design of TMN for the large signal. The objective is to present at the output of a power amplifier, the impedances that optimize efficiency for each power of operation. A 130 nm SOI prototype was designed and simulated, consisting of a power amplifier for WCDMA standard, 900 MHz, and a MN tunable by MOS varactors able to produce the optimal impedances corresponding to an output power between 20 and 30 dBm. The results showed the benefit provided by inserting a tunable MN compared to a fixed one.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Integrated Silicon Microwave and Millimeterwave Passive Components and Functions

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Contributions aux circuits de « gate-driver » dédiés aux transistors de puissance à forte vitesse de commutation dans un environnement haute temperature

International audienceBasé sur les contraintes de fonctionnement des transistors à commutations rapides, cet article présente et analyse la problématique du transfert des ordres de commande du transistor « high-side » dans une configuration de bras d'onduleur. En plus des contraintes imposées par les forts « dv/dt » sur le driver, la température de fonctionnement élevée (jusqu'à 200°C) impose une conception spécifique du circuit de commande. Aujourd'hui, la technologie silicium reste la solution la plus fiable et la plus mature pour la conception du driver mais au prix d'une mise en œuvre délicate (tenue en tension, température, dv/dt). Trois solutions sont proposées et comparées : transformateur coreless, level-shifter et émetteur/récepteur optique. Les délais de propagation, l'intégrité du signal (durée du rapport cyclique et précision temporelle) ainsi que l'immunité aux dv/dt des prototypes sont caractérisées en fonction de la température ambiante de fonctionnement.</p

Ki-67: level of evidence and methodological considerations for its role in the clinical management of breast cancer: analytical and critical review

Clinicians can use biomarkers to guide therapeutic decisions in estrogen receptor positive (ER+) breast cancer. One such biomarker is cellular proliferation as evaluated by Ki-67. This biomarker has been extensively studied and is easily assayed by histopathologists but it is not currently accepted as a standard. This review focuses on its prognostic and predictive value, and on methodological considerations for its measurement and the cut-points used for treatment decision. Data describing study design, patients’ characteristics, methods used and results were extracted from papers published between January 1990 and July 2010. In addition, the studies were assessed using the REMARK tool. Ki-67 is an independent prognostic factor for disease-free survival (HR 1.05–1.72) in multivariate analyses studies using samples from randomized clinical trials with secondary central analysis of the biomarker. The level of evidence (LOE) was judged to be I-B with the recently revised definition of Simon. However, standardization of the techniques and scoring methods are needed for the integration of this biomarker in everyday practice. Ki-67 was not found to be predictive for long-term follow-up after chemotherapy. Nevertheless, high KI-67 was found to be associated with immediate pathological complete response in the neoadjuvant setting, with an LOE of II-B. The REMARK score improved over time (with a range of 6–13/20 vs. 10–18/20, before and after 2005, respectively). KI-67 could be considered as a prognostic biomarker for therapeutic decision. It is assessed with a simple assay that could be standardized. However, international guidelines are needed for routine clinical use

The C-terminal loop of the homing endonuclease I-CreI is essential for site recognition, DNA binding and cleavage

Meganucleases are sequence-specific endonucleases with large cleavage sites that can be used to induce efficient homologous gene targeting in cultured cells and plants. These enzymes open novel perspectives for genome engineering in a wide range of fields, including gene therapy. A new crystal structure of the I-CreI dimer without DNA has allowed the comparison with the DNA-bound protein. The C-terminal loop displays a different conformation, which suggests its implication in DNA binding. A site-directed mutagenesis study in this region demonstrates that whereas the C-terminal helix is negligible for DNA binding, the final C-terminal loop is essential in DNA binding and cleavage. We have identified two regions that comprise the Ser138–Lys139 and Lys142–Thr143 pairs whose double mutation affect DNA binding in vitro and abolish cleavage in vivo. However, the mutation of only one residue in these sites allows DNA binding in vitro and cleavage in vivo. These findings demonstrate that the C-terminal loop of I-CreI endonuclease plays a fundamental role in its catalytic mechanism and suggest this novel site as a region to take into account for engineering new endonucleases with tailored specificity

A compilation of charged-particle induced thermonuclear reaction rates

Low-energy cross section data for 86 charged-particle induced reactions involving light (1 less than or equal to Z less than or equal to 14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 10(6) K to 10(10) K are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided. (C) 1999 Elsevier Science B.V. All rights reserved

A whole-genome sequence and transcriptome perspective on HER2-positive breast cancers.

HER2-positive breast cancer has long proven to be a clinically distinct class of breast cancers for which several targeted therapies are now available. However, resistance to the treatment associated with specific gene expressions or mutations has been observed, revealing the underlying diversity of these cancers. Therefore, understanding the full extent of the HER2-positive disease heterogeneity still remains challenging. Here we carry out an in-depth genomic characterization of 64 HER2-positive breast tumour genomes that exhibit four subgroups, based on the expression data, with distinctive genomic features in terms of somatic mutations, copy-number changes or structural variations. The results suggest that, despite being clinically defined by a specific gene amplification, HER2-positive tumours melt into the whole luminal-basal breast cancer spectrum rather than standing apart. The results also lead to a refined ERBB2 amplicon of 106 kb and show that several cases of amplifications are compatible with a breakage-fusion-bridge mechanism