Remotely powered addressable UHF RFID integrated system

This paper presents a fully integrated remotely powered and addressable radio frequency identification (RFID) transponder working at 2.45 GHz. The achieved operating range at 4 W effective isotropically radiated power (EIRP) base-station transmit power is 12 m. The integrated circuit (IC) is implemented in a 0.5 /spl mu/m silicon-on-sapphire technology. A state-of-the-art rectifier design achieving 37% of global efficiency is embedded to supply energy to the transponder. The necessary input power to operate the transponder is about 2.7 /spl mu/W. Reader to transponder communication is obtained using on-off keying (OOK) modulation while transponder to reader communication is ensured using the amplitude shift keying (ASK) backscattering modulation technique. Inductive matching between the antenna and the transponder IC is used to further optimize the operating range.     

High speed BiCMOS current mode differential track-and-hold circuit

A new principle for a high speed BiCMOS differential track-and-hold circuit based on current mode processing is presented, and simulation results are given. The main characteristics are an acquisition time of 5.5 ns for 8 bit precision and a small-signal bandwidth of 1 GHz     

An EKV-based high voltage MOSFET model with improved mobility and drift model

An EKV-based high voltage MOSFET model is presented. The intrinsic channel model is derived based on the charge based EKV-formalism. An improved mobility model is used for the modeling of the intrinsic channel to improve the DC characteristics. The model uses second order dependence on the gate bias and an extra parameter for the smoothening of the saturation voltage of the intrinsic drain. An improved drift model [Chauhan YS, Anghel C, Krummenacher F, Ionescu AM, Declercq M, Gillon R, et al. A highly scalable high voltage MOSFET model. In: IEEE European solid-state device research conference (ESSDERC), September 2006. p. 270–3; Chauhan YS, Anghel C, Krummenacher F, Maier C, Gillon R, Bakeroot B, et al. Scalable general high voltage MOSFET model including quasi-saturation and self-heating effect. Solid State Electron 2006;50(11–12):1801–13] is used for the modeling of the drift region, which gives smoother transition on output characteristics and also models well the quasi-saturation region of high voltage MOSFETs. First, the model is validated on the numerical device simulation of the VDMOS transistor and then, on the measured characteristics of the SOI-LDMOS transistor. The accuracy of the model is better than our previous model [Chauhan YS, Anghel C, Krummenacher F, Maier C, Gillon R, Bakeroot B, et al. Scalable general high voltage MOSFET model including quasi-saturation and self-heating effect. Solid State Electron 2006;50(11–12):1801–13] especially in the quasi-saturation region of output characteristics.     

Aging and inhibition processes: The case of metaphor treatment.

The inhibitory deficit hypothesis has often been cited as a possible explanation for cognitive changes related to age. The aim of this study was to develop a new procedure for evaluating effortful inhibition on the basis of the comprehension of metaphors. Our experiment was carried out on younger and older adults, in whom we also measured inhibitory capacity, working memory, and processing speed. The results show that older participants required a longer time and made more frequent errors in rejecting metaphors versus literally false statements. The interference effect was predicted by the psychometric tests designed to evaluate inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxidative catabolism of α-tocopherol in rat liver microsomes

The goal of this study was to clarify the mechanism responsible for the catabolism of α-tocopherol. The vitamin, bound to albumin, was incubated with rat liver microsomes and appeared to be broken down. Optimal production of the metabolite was obtained when 1 mg of microsomal protein was incubated with 36 μM of α-tocopherol in the presence of 1.5 mM of NADPH. Chromatographic and mass spectrometric analyses of the metabolite led to the conclusion that it consists of an ω-acid with an opened chroman ring, although we could not perform nuclear magnetic resonance analysis to confirm this. Our data show that α-tocopherol is ω-oxidized to a carboxylic acid and that this process can occur in rat liver microsomes in the presence of NADPH and O₂. The oxidation to the quinone structure appears to be a subsequent event that may be artifactual and/or catalyzed by a microsomal enzyme(s).     

A highly flexible sea-of-gates structure for digital and analogapplications

A sea-of-gates structure optimized for digital random logic applications as well as for regular arrays and analog circuits is described. Associated with a dedicated design procedure and a systematic metallization strategy, the structure features a full cell-abutment capability and true channelless routing. After reviewing the advantages and limitations of currently available arrays, the main characteristics of the array architecture are presented, and applications to different circuit families are detailed. Design automation tools suited to the structure and design methodology are reviewed. Design results and performance are presented for several macroblocks and are compared with other semicustom approaches. A set of rules which allows an automatic transformation of the sea-of-gates layout into a topologically equivalent full-custom layout, converting semicustom prototypes to full-performance circuits, is presented     

A fast Modulator for dynamic supply linear RF power amplifier

A fast modulator for a dynamic supply linear RF amplifier has been integrated in a 0.35-/spl mu/m CMOS technology. The use of this modulator with an external linear power amplifier (PA) allows to maintain its efficiency at a higher level than it would with the same PA supplied at constant voltage. The modulator is designed to follow rapid envelope variations at high efficiency without compromising the RF PA linearity.     

Differential role of calcium in tumour necrosis factor-mediated apoptosis and secretion of granulocyte-macrophage colony-stimulating factor in a T cell hybridoma

The authors investigated the dependence on extracellular and intracellular free Ca2+ in the induction of apoptosis and secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) by tumour necrosis factor (TNF) in a rat/mouse T cell hybridoma PC60 R55/R75, using the Ca2+ chelators EGTA and BAPTA/AM, respectively. TNF-induced apoptosis still occurred in the absence of free Ca2+, while GM-CSF production required the continuous presence of Ca2+. The latter was also true for GM-CSF production driven by interleukin 1 (IL-1). The dependence on Ca2+ in the induction of GM-CSF, but not of apoptosis, was further confirmed by the inhibition of TNF- or IL-1-induced cytokine production by cyclosporin A or FK506, drugs that block the Ca2+/calmodulin-dependent protein Ser/Thr phosphatase calcineurin. This differential requirement for Ca2+ illustrates the partial functional redundancy between TNF and IL-1, showing the activation of cytokine gene expression through a Ca(2+)-dependent activation of calcineurin, and a Ca(2+)-independent activation of apoptosis, exerted solely by TNF.     

A 1.5-V-supplied CMOS ASIC for the actuation of an electrostaticmicromotor

The use of electrostatic forces in micromechanical systems is well known, but quite high voltages are needed to produce usable forces. In this perspective paper, a 1.5-V battery-supplied integrated circuit able to drive an electrostatic micromotor is presented. The application-specific integrated circuit (ASIC) can output signals up to 80 V, with low-voltage controlling signals. It is especially designed for portable (wristwatch-like) applications. High voltage can be produced by either switching or charge-pumping power supplies     

Design of regular (2,d/sub c/)-LDPC codes over GF(q) using their binary images

In this paper, a method to design regular (2, d_c)- LDPC codes over GF(q) with both good waterfall and error floor properties is presented, based on the algebraic properties of their binary image. First, the algebraic properties of rows of the parity check matrix H associated with a code are characterized and optimized to improve the waterfall. Then the algebraic properties of cycles and stopping sets associated with the underlying Tanner graph are studied and linked to the global binary minimum distance of the code. Finally, simulations are presented to illustrate the excellent performance of the designed codes.