1,720,995 research outputs found
Analysis and Design of D-Band Cascode SiGe BiCMOS Amplifiers with Gain-Bandwidth Product Enhanced by Load Reflection
No full textEmerging applications in D-band (110-170GHz) demand amplifiers with high gain-bandwidth (GBW) products. In this frequency range, the cascode stage offers superior available gain, thanks to the high output impedance, but the design of the output matching network entails a GBW tradeoff. The issue is deeply investigated in this work. Simple, closed-form equations for gain and bandwidth as a function of the load reflection coefficient are derived, leading to the following design insights: 1) for maximum gain and bandwidth, the output matching network should be implemented with positive (magnetic) reactances; 2) with lossy reactances, an optimal load reflection coefficient exists to maximize the power gain, Γ L-opt; and 3) by selecting Γ L < Γ L-opt, the bandwidth increases quickly with a marginal gain penalty, finally enhancing the GBW product. Leveraging the results of the analysis, single-stage and multistage stagger-tuned amplifiers are implemented in SiGe BiCMOS technology. Two-and three-stage amplifiers demonstrate more than 60GHz bandwidth with 20 and 28dB gain, respectively, corresponding to 700GHz and 1.7 THz GBW. Normalizing gain and bandwidth to the number of stages and technology f the resulting figure of merit is remarkably higher than previously reported silicon amplifiers in the same band
150 GHz Differential Amplifiers with Lumped-Elements Matching Networks in 55 nm SiGe BiCMOS
No full textThis paper presents compact D-band amplifiers in 55 nm SiGe BiCMOS technology. Device models and design tools are first validated with measurements on elementary components above 100 GHz. Then, amplifiers are designed leveraging lumped components in matching networks for minimum area occupation. A differential topology is developed for robustness against parasitic effects of the non-ideal ground, a key issue with lumped components at high frequency. Experimental results are in very good agreement with simulations. The 1-stage amplifier reaches 8 dB gain at 156 GHz and 17.8 GHz bandwidth in 0.026 mm2 silicon area. The 2-stage amplifier displays 17.4 dB gain at 157 GHz with 42.7 GHz bandwidth in 0.048 mm2. Compared to previously reported SiGe amplifiers in similar frequency range, more than 2x core area reduction is demonstrated at comparable gain-bandwidth product
Design of Compact D-Band Amplifiers with Accurate Modeling of Inductors and Current Return Paths in 55-nm SiGe BiCMOS
No full textThis letter presents 1-stage and 2-stage compact D-band amplifiers with lumped-element matching networks implemented in 55 nm SiGe BiCMOS. To correctly account for the effects of a nonideal ground plane, i.e., reactances in current return paths, and coupling of inductors with nearby layout structures, a shielded 2-port, 4-terminal simulation strategy for inductors is proposed. Validated by measurements, the approach allows very accurate design of compact amplifiers in D-band. The 1-stage design proves 11.8 dB gain at 152 GHz and 17.9 GHz bandwidth in 0.031 mm2. With the 2-stage amplifier, featuring 20.1 dB gain at 150 GHz with 24.5 GHz bandwidth in 0.058 mm2, from 2 imes to 5.7 imes area reduction is demonstrated against similar SiGe amplifiers in the same frequency band
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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