1,720,974 research outputs found
A bias network for small duty-cycle fast-pulsed measurement of RF power transistors
No full textRadio-frequency power transistors affected by dispersive phenomena such as thermal and charge trapping effects can be effectively characterized and modeled by means of pulsed current-voltage measurements. This work presents the design of a passive bias network made out of off-the-shelf components and tailored for the application of fast pulses through its capacitive path, yet extending the bandwidth down to a few kHz. This custom component enables small duty-cycle (e.g., 0.1 %) fast-pulsed excitations of several tens of V of ac voltage in the presence of bias voltages up to 50 V and bias currents up to 2 A
Behavioral Model for Voltage Controlled Oscillators
No full textBehavioral Model for Voltage Controlled Oscillator
Implementation of non-conventional nonlinear models for electron devices in commercial CAD tools
No full textIn nowadays CAD environments for
integrated microwave circuit design, dedicated tools for the
implementation of user defined component models are
becoming more and more important. These tools are mainly
oriented to the definition of equivalent circuit models.
However, the need for more accurate prediction of nonlinear electron device performance pushes the modelling community towards the research of new, often nonconventional, modelling approaches (e.g., frequencydomain, behavioural, integral models, look-up-table based, state-space based, etc.). In such a context, the model implementation tools usually available may result not sufficiently flexible. The paper provides useful hints and points out the main limitations which can be encountered in the implementation of non-conventional electron device models. As an example, the implementation of a Nonlinear Discrete Convolution model will be considered by using three different advanced tools: the Model Wizard of AWR Microwave Office, the Model Development Kit and Verilog- A Language of Agilent ADS
Measurement-Based Automatic Extraction of FET Parasitic Network by Linear Regression
No full textA fully automatic procedure for the empirical extraction of field-effect transistors (FETs) parasitic network is proposed. By exploiting a grid search approach combined with linear regression, the identification requires Y-parameter measurements at a very few (even just one) bias points. The method is verified in simulation and applied to measurements of a 250-nm GaN high-electron-mobility transistor (HEMT)
A distributed approach for millimetre-wave electron device modelling
No full textElectron device modelling at very high frequencies needs, as a preliminary step, the identification of suitable parasitic elements mainly describing the passive structure used for accessing the intrinsic device. However, when dealing with device modelling at millimetre-wave frequencies conventional lumped parasitic networks necessarily become less adequate in describing inherently distributed parasitic phenomena. In this paper, a distributed approach is adopted for the modelling of the parasitic network and a new identification procedure, based on electromagnetic simulation and conventional S-parameter measurements, is proposed. The intrinsic device, obtained after de-embedding from the distributed parasitic network, is particularly suitable for the extraction of accurate nonlinear models. Preliminary validation results are provided in the paper. © 2006 EuMA
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
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