RF CMOS body-effect circuits

After a theoretical and analytical study of the body effect in MOS transistors, this paper offers two useful models of this parasitic phenomenon. Thanks to these models, a design methodology, which takes advantage of the bulk terminal, allows to turn this well-known body-effect drawback into an analog advantage, giving thus an efficient alternative to overcome the design constraints of the CMOS VLSI wireless mass market. To illustrate the approach, four RF building blocks are presented. First, a 0.9 V 10 dB gain LNA, covering a frequency range 1.8-2.4 GHz, thanks to a body-effect common mode feedback, is detailed. Secondly, a body-effect linearity controlled pre-power amplifier is presented exhibiting a 5 dB m input compression point (ICP1) variation under 1.8 V power supply for half the current consumption. Lastly, two mixers based on body-effect mixing are presented, which achieve a 10 dB conversion gain under 1.4 V for a −52 dB LO-to-RF isolation. Well suited for low-power/low-voltage applications, these circuits implemented in a 0.18 μm CMOS VLSI technology are dedicated to multi-standard architectures and system-on-chip implementations.     

The BNM-LPTF software for the frequency comparison of atomic clocks by the carrier phase of the GPS signal

This paper describes the software and equipment used at the Laboratoire Primaire du Temps et des Frequences du Bureau National de Metrologie (BNM-LPTF), Paris, France. Two H-masers in short baseline, one located at the BNM-LPTF and the other at the Laboratoire de l'Horloge Atomique du Centre National de la Recherche Scientifique (CNRS-LHA), Orsay, France, were computed in parallel with the BNM-LPTF software and with the BERNESE V 4.1 software. The comparison of the results issued from both computations shows an agreement within 100 ps (1 sigma). In addition, comparisons with the BNM-LPTF software were made over 10 days with the H-masers located at the Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany, and another at the National Physical Laboratory (NPL), Teddington, United Kingdom. The data collected show that a modulation with an amplitude of 50 ps and a period of 700-800 ps affects the equipment of the NPL. In addition, these comparisons show that the noise of the instruments together with the environmental conditions at the PTB was higher than that of the NPL and the BNM-LPTF during the observation period. The best relative frequency stability obtained, in the BNM-LPTF/NPL comparison, is about 3x10(-15) for averaging periods between 6x10(4) s and 3x10(5) s. This result is in good agreement with the expected stability of H-masers. It demonstrates that the noise brought by the GPS carrier phase measurements can be averaged out at this level.     

Take care! The evaluation of a team-based burnout intervention program for oncology care providers.

In this quasi-experimental study among staff of 29 oncology wards, the authors evaluated the effects of a team-based burnout intervention program combining a staff support group with a participatory action research approach. Nine wards were randomly selected to participate in the program. Before the program started (Time 1), directly after the program ended (Time 2), and 6 months later (Time 3), study participants filled out a questionnaire on their work situation and well-being. Results of multilevel analyses showed that staff in the experimental wards experienced significantly less emotional exhaustion at both Time 2 and Time 3 and less depersonalization at Time 2, compared with the control wards. Moreover, changes in burnout levels were significantly related to changes in the perception of job characteristics over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How may nonresponse affect findings in organizational surveys? The tendency-to-the-positive effect.

Building on previous findings that those who hold negative attitudes toward the organization have a relatively low likelihood to participate in organizational surveys, the authors examined the impact of nonresponse on the findings of organizational surveys. An artificial example showed that if the likelihood to respond depends on one's standing on response-related variables, the scores on these latter variables will differ from those for the population, whereas between-organization differences in these variables will be underestimated. Consistent with earlier findings, our survey among employees of 96 Dutch home care organizations revealed that employees of high-response organizations reported more positive attitudes toward their work and organization than others. This underlines the importance of obtaining high response rates in organizational studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A multigroup analysis of the job demands-resources model in four home care organizations.

The job demands-resources (JD-R) model was tested in a study among 3,092 employees working in 1 of 4 different home care organizations. The central assumption in the model is that burnout develops when certain job demands are high and when job resources are limited because such negative working conditions lead to energy depletion and undermine worker motivation and learning opportunities, respectively. A series of multigroup structural equation modeling analyses provide strong evidence for the JD-R model. Specifically, results showed that job demands are primarily and positively related to the exhaustion component of burnout, whereas job resources are primarily related to cynicism (negatively) and professional efficacy (positively). The theoretical and practical implications of the JD-R model are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From inequity to burnout: The role of job stress.

This research examined burnout (i.e., emotional exhaustion, depersonalization, and lack of personal accomplishment) among 2 samples of Dutch teachers as a function of inequity and experienced job stress in 3 different exchange relationships (with students, colleagues, and the school). It was hypothesized that inequity would he linked to burnout through the stress resulting from this inequity. Analysis of a cross-sectional sample (N?=?271) revealed that this was indeed the case. Findings were replicated longitudinally using an independent sample of 940 teachers. It is concluded that the often-reported effect of inequity on burnout can partly be interpreted in terms of elevated levels of job stress. Implications of the findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On gender specificity of person characteristics in personnel advertisements: a study among future applications

This research is an examination of how person characteristics mentioned in personnel advertisements influence the judgments of male and female students with regard to their subjective eligibility for, and the attractiveness of, a particular vacancy. The first study showed that many frequently mentioned person characteristics in personnel advertisements applied differently to men and women, but that female characteristics were more in demand than male characteristics. The second study examined to what degree male and female participants felt that they themselves possessed male and female characteristics; results showed that the men were more confident about the degree to which they possessed male and female characteristics than the women were. The third study examined how the type of person characteristics mentioned in personnel advertisements influenced men's and women's judgments regarding their eligibility for and the attractiveness of a particular position. The men found all positions about equally attractive, whereas the women found "male" positions considerably less attractive. Implications of the study are discussed.     

Microwave-based biosensor for on-chip biological cell analysis

This paper presents an innovative biosensing technique, based on the interaction between biomaterial and microwave electromagnetic (EM) waves, which probes the bio-parameters of investigated biological samples. Thanks to the microtechnologies, this approach is able to sense biomaterials down to living cells size without invasivity. The broadband dielectric spectroscopy of living cells suspensions is therefore demonstrated, sketching a rich EM signature, “rich” in terms of biological information’s such as cells’ proliferation and cells’ viability. Capacitive contrasts of 4 and 12 % between the cells suspension and their pure medium are measured at 20 and 40 GHz respectively, which demonstrate the ability of such a technique to detect (and quantify) living cells non-invasively. Moreover, we demonstrate a capacitive contrast of 5 % at 30 GHz between living and dead cells. Such a result is based on the ability of the microwaves to penetrate into the cells and sense their intracellular content, and then to carry viability information’s of biomaterials out. Finally, we present the feasibility of on-chip microwave signals processing, which points out that integrated circuit for data processing can be integrated together with a nano-liter range microfluidic bio-sample manipulation and a microwave-based biosensor. Such a work consequently permits to envision promising Lab-on-Chip applications such as cells’ drug screening for personalized medicine notably.     

Current reuse topology in UWB CMOS LNA

Low power low voltage operation is found to be the bottleneck of future CMOS system implementations. To comply with these constrains, a current reuse configuration is here reported to design UWB Low Noise Amplifiers (LNA). A resistive feedback topology is first proposed performing an 11.5 dB gain over a 2 to 9 GHz range. Consuming a 17 mW under 1.4 V, this circuit achieves a 4.45 dB minimum Noise Figure (NFmin). Current reuse approach is then combined with LC ladder technique to cover the upper band of European UWB—i.e. 6 to 10 GHz-. This second LNA provides a 12.2 dB, 4.4 dB NFmin, from 5.6 to 8.8 GHz. Operating under 1.6 V it solely consumes 5 mW. Considering a 1.2 V supply voltage case, the two circuits still exhibit a more than 9 and 11 dB gain respectively. Implemented in a 0.13 μm CMOS technology, silicon areas are 0.6 mm2 for resistive feedback amplifier, and 1 mm2 for LC ladder, with PADS.