1,720,974 research outputs found
A Magnetically Tuned Quadrature Oscillator
No full textContinuous frequency tuning by control of the magnetic field of a transformer—capacitor tank, in a selective oscillator, is explored in this work. A quadrature generator is built connecting two identical transformer—capacitor oscillator cells in a feedback loop. The topology itself assures the currents in the transformer windings are aligned in phase, while their relative amplitude determines, via magnetic coupling, oscillators’ tank reactance,i.e., oscillation frequency. This paper introduces the idea, analyzesoscillation amplitude, frequency tuning band, phase noise, and phase accuracy, and discusses design and experiments. Prototypes,realized in 65 nm CMOS, employing MOS varactors to further extend operation bandwidth, show the following performances:3.2 GHz and 7.3 GHz minimum and maximum oscillation orequency, respectively. Phase noise figure of merit of 176.5 dBat 3.2 GHz and 170.5 dB at 6.4 GHz is observed, with 24 mWmaximum power consumption and 1.5 maximum deviation fromquadrature
A 24GHz Sub-Harmonic Receiver Front-End with Integrated Multi-Phase LO Generation in 65nm CMOS
No full textA sub-harmonic architecture for wireless signal processing at Ka band is proposed resulting in IC power saving because the LO circuits operate at half frequency and no IF stage is necessary. A 65nm CMOS prototype, including High Frequency front-end, base-band amplifier and multi-phase VCO and dividers, shows: 31.5dB gain, 6.5dB NF, -17dBm IIP3, -90dBm LO re-irradiation at 24GHz, while consuming 92mW
A Lumped Element Phisical Model for Symetrical Spiral Inductors and their Cross-Talk in silicon RFICs
No full textModern RFICs have achieved an impressively high integration level, making cross-coupling effects among different sections of the circuit a potential limit to their functionality. Integrated spiral inductors occupy a significant chip area and are a potential source of EM interference. This paper investigates the coupling effects between two planar spiral inductors. A physical model for the single inductor is introduced, valid for any kind of excitation (single-ended, differential and also common-mode). The model is then extended to correctly reproduce the coupling behavior under any kind of excitation
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
A 24 GHz Subharmonic Direct Conversion Receiver in 65 nm CMOS
No full textScaled CMOS proves to be suitable for the design of transceiver ICs at micro- and millimeter-waves. The effort is presently toward compact and low-power solutions in view of integrating several transceivers on the same chip enabling phased array systems. In this paper we present a 24 GHz receiver, based on a subharmonic direct conversion architecture, designed in a 65 nm node. The local oscillator takes advantage of the half frequency operation proving significantly lower power consumption when compared to conventional solutions running at received frequency. Stacked switches for subharmonic down-conversion are passive to save voltage room, current driven and loaded by a transresistance amplifier. Optimum biasing of the switches allows maximizing linearity while saving power in the baseband. The integrated LNA matching network is the bottleneck toward low sensitivities. The LNA design trades-off power consumption, gain and sensitivity. Detailed insights into implementation issues, critical in a single-ended topology where both forward and return signal paths have to be supported, are provided. The chip consumes 78 mW and occupies 1.4 mm2 of active area. Experiments show: 30.5 dB gain, 6.7 dB NF, -13 dBm IIP3
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
- …
