1,721,137 research outputs found
Polymer microwave fibers: a new approach that blends wireline, optical, and wireless communication
No full text
Alternative concepts for wideband Doherty power amplifiers
No full textAs we increasingly develop on technologies such as autonomous driving, Industry 4.0, and cloud computing, the need for reliable and high-speedwireless communication is more crucial than ever. However, increasing the frequency bandwidths and centre frequencies of wireless communication systems to achieve higher data rates leads to physical limitations on the receive input power of RF receivers. To overcome these limitations, the next generation of wireless communication will combine multiple antennas to an active beamforming transceiver system. This is technically challenging, particularly for the power amplifiers, which need to provide high bandwidth, be small in size, and perform energy-efficient amplification for complex modulated signals. In this thesis, the author explores the use of the Doherty power amplifier (DPA) as a potential solution to these challenges. While DPAs have some limitations in terms of bandwidth and area consumption, they are promising to increase the overall energy efficiency of the transceiver system. The author proposes alternative architectures, which promise to provide higher frequency bandwidth and high integrability. Through the development of three prototypes using complementary metal-oxide- semiconductor (CMOS), gallium nitride (GaN) monolithic microwave integrated circuit (MMIC), and hybrid design technologies, the author demonstrates the potential of these wideband designs with 5 dB to 10 dB output power backoff (OBO) while also reducing the area consumed in all used technologies. The proposed architecture also leads to the smallest transmission line based DPA combiners ever reported, which paves the way for energy-efficient, high power amplifiers with highest integration capability
Novel broadband transition for rectangular dielectric waveguide to planar circuit board at D-band
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
- …
