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Blaise Ravelo

Bio: Blaise Ravelo is an academic researcher from Nanjing University of Information Science and Technology. The author has contributed to research in topics: Group delay and phase delay & Microstrip. The author has an hindex of 21, co-authored 196 publications receiving 1727 citations. Previous affiliations of Blaise Ravelo include École Supérieure d'Ingénieurs en Génie Électrique & Nanjing University.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the design, simulation and implementation of an active negative group delay circuit that operates at 1 GHz with a group delay and a gain, respectively, around 2 ns and 2 dB.
Abstract: In this letter, we report on the design, simulation and implementation of an active negative group delay circuit that operates at 1 GHz with a group delay and a gain, respectively, around 2 ns and 2 dB. Analytical formulas are proposed to demonstrate that the adopted topology is able to simultaneously achieve negative group delay (NGD) and gain while fulfilling active device constraints. The theoretical and simulated results are both validated by frequency measurements of a two-stage active microwave circuit.

88 citations

Journal ArticleDOI
TL;DR: The introduced transform relationships simplify the synthesis of any NGD circuits from simple elementary low-pass NGD topologies, and the possibility of the ultra-wideband pulse signals propagating in time-advance is verified.
Abstract: This paper deals with the similitude between the behaviours of linear filter gain and negative group delay NGD function. The transposition method of low-pass/high-pass, low-pass/band-pass and low-pass/band-stop NGD circuits is established. To the best of the author knowledge, it acts as the first paper devoted on the NGD function generalized theory. The introduced transform relationships simplify the synthesis of any NGD circuits from simple elementary low-pass NGD topologies. Families of innovative NGD topologies are identified. To verify the relevance of the concept proposed, frequency- and time-domain analysis results from realistic proofs of concept demonstrating the feasibility of developed NGD transforms were performed. Thanks to the NGD phenomenon, the possibility of the ultra-wideband pulse signals propagating in time-advance is verified. Finally, potential applications of NGD circuits are discussed. Copyright © 2013 John Wiley & Sons, Ltd.

82 citations

Journal ArticleDOI
TL;DR: A detailed review of the various synthesis and characterization techniques for the production of the nanoparticles can be found in this paper, where the authors highlight the unlimited potential of nanoparticles and their derivatives in the domain of contaminated and wastewater treatment.

80 citations

Proceedings ArticleDOI
03 Jun 2007
TL;DR: In this paper, the design and synthesis of active circuits able to simultaneously produce negative group delay and gain at microwave frequencies or for baseband signals is discussed, and a synthesis approach is extracted and applied to design a two-stage microwave circuit, further validated by experimental results.
Abstract: This paper deals with the design and synthesis of active circuits able to simultaneously produce negative group delay and gain at microwave frequencies or for baseband signals Analytical equations show that the proposed topology meets these objectives while also satisfying active device requirements Then, a synthesis approach is extracted and applied to design a two-stage microwave circuit, further validated by experimental results This method is extended to the design of a four-stage baseband active circuit providing gain and negative group delay up to 600 MHz A high relative time-advance is evidenced by time-domain simulations

69 citations

Journal ArticleDOI
TL;DR: In this article, a fundamental theory of coupled line coupler-based negative group delay (NGD) topology is established, which consists of the isolated-and coupled-accesses connected in a feedback loop through a lossy interconnect line.
Abstract: A fundamental theory of coupled line coupler-based negative group delay (NGD) topology is established in this paper. The microwave circuit under study consists of the isolated-and coupled-accesses connected in a feedback loop through a lossy interconnect line. The NGD topology is built with fully distributed elements. The S-parameter model is formulated in order to derive the NGD optimal values, cutoff frequencies, and bandwidth. Thus, the NGD existence condition as a function of the coupling coefficient and the feedback interconnection attenuation is demonstrated and examined. Hence, the fundamental characteristics of the coupler-based NGD topology are described. In order to verify the feasibility of the theory, NGD prototypes were designed, fabricated, and measured. The implemented one- and two-stage microstrip circuits have NGDs of about −2.3 and −4 ns, respectively, at 1.26 GHz. The reflection coefficients are better than 10 dB and the insertion losses are, respectively, about 2.4 and 4.3 dB. The developed NGD topology, fully constructed with distributed elements without any lumped components, is particularly beneficial in terms of design simplicity. The proposed NGD circuit might find potential application in microwave signal delay correction.

68 citations


Cited by
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Book
01 Jan 1960

1,106 citations

Journal ArticleDOI
TL;DR: This is really two separate books within the same pair of covers, which are devoted to the discussion of similarity and dimensional, methods and their application to a variety of problems in mechanics and fluid mechanics.
Abstract: By L I Sedov London: Cleaver-Hume Press Ltd Pp xvi + 363 Price 105s This is really two separate books within the same pair of covers First of all Chapters 1-3, some 145 pages, are devoted to the discussion of similarity and dimensional, methods and their application to a variety of problems in mechanics and fluid mechanics

697 citations

Journal ArticleDOI
01 Nov 1951-Nature
TL;DR: In this article, Sommerfeld presents a review of the theoretic aspects of Physik, including Mechanik, Elektrodynamik and Partielle Differentialgleichungen der Physik.
Abstract: Vorlesungen uber theoretische Physik Von Prof. Arnold Sommerfeld. Band 1: Mechanik. Vierte, neubearbeitete Auflage. Pp. xii + 276. 18 D. marks. Band 2: Mechanik der deformierbaren Medien. Pp. xv + 376 + 4 plates. 18 D. marks. Band 3: Elektrodynamik. Pp. xvi + 368. 18 D. marks. Band 6: Partielle Differentialgleichungen der Physik. Pp. xiii + 332. 18 D. marks. (Wiesbaden: Dieterich'sche Verlagsbuchhandlung, 1947–1949.)

669 citations

Journal ArticleDOI
TL;DR: A new prototype triboelectric nanogenerator with superhydrophobic and self-cleaning features is invented to harvest water drop energy based on a sequential contact electrification and electrostatic induction process.
Abstract: A new prototype triboelectric nanogenerator with superhydrophobic and self-cleaning features is invented to harvest water drop energy based on a sequential contact electrification and electrostatic induction process. Because of the easy-fabrication, cost-effectiveness, and robust properties, the developed triboelectric nanogenerator expands the potential applications to harvesting energy from household wastewater and raindrops.

544 citations