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.

Modélisation multiphysique : premiers concepts fondamentaux dans le cadre classique

Abstract: L'objet de cet article est de presenter quelques premieres tentatives de modelisation multiphysique basees sur l'analyse tensorielle des reseaux pour realiser des etudes amonts. Nous presentons le formalisme detaille pour considerer un systeme electro-thermo-mecanique. L'objectif est de se doter d'une expression generalisee de la variete associee a un tel systeme. Dans l'approche proposee, la temperature apparait comme un parametre au meme titre que le temps, ces parametres permettent de determiner la courbure de l'espace lorsque les operateurs qui s'appliquent aux flux dependent de la temperature. Nous pouvons noter que ce comportement est tout a fait general au-dela de certaines limites en temperature. Cette affirmation montre que les espaces physiques sont toujours courbes meme dans le cadre de la mecanique classique.

"Negative group delay experimentation with tee connector and cable structures", Eur. Phys. J. Appl. Phys. (EPJAP)

Abstract: The unfamiliar negative group-delay (NGD) phenomenon is experimented with structure constituted by tee-connectors and coaxial cables. The topology of the NGD generator is described. It consists of two parallel 50-Ω characteristic impedance cables. The S-parameter model in function of the cable physical lengths is established. The existence condition enabling to understand the NGD phenomenon is defined. A proof of concept simply is constituted by two three-port SMA connectors, three SMA transitions and 13-cm length cables. The NGD experimentation is performed from 1.5 GHz to 3.5 GHz. Tri-band NGD aspects in good agreement with the theory and simulation is observed experimentally. Particularly, high figure-of-merit NGD circuit with-3 ns NGD level, less than 2 dB insertion loss and 12 dB return loss around 3 GHz centre frequency is measured.-Sebastien Lallechere performed result verifications by simulation.-Blaise Ravelo was the main initiator of the NGD cable-connector structure and the development of the NGD theory.-All authors contributed on the article writing with critical reviews and corrections.

Analysis, design and implementation of a hybrid three-port switchable power splitter (SPWS) on Kapton flexible substrate

Abstract: A topology of switchable power splitter (SPWS) ink-jet printed on flexible Kapton substrate is developed in this paper. The SPWS circuit diagram integrating a Tee PWS is described based on the synoptic approach. The complete theoretical formulations of the SPWS reflection and transmission coefficients were established. The analytical expressions enabling to assess the Tee-PWS elementary output lines for the SPWS input matching are elaborated. To validate the relevance of the proposed SPWS, a proof of concept was synthesized, designed and implemented in microstrip hybrid technology by using the packaged switch biased with 3.3 V DC supply. The fabricated circuit was directly ink-jet printed on a low cost flexible Kapton® polyimide film, using a Dimatix DMP-2831 materials printer. Then, comparisons between the experimental and electromagnetic and circuit co-simulated S-parameters from the SPWS prototype were performed. The measured SPWS performance to operate in the IEEE standard 802.11a bands from 5.4-5.7 GHz was presented. The SPWS presents overall insertion losses of about-5.5 dB and-13 dB respectively for the switches on-and off-state. Furthermore, the input and output return losses are respectively with average value of about-11 dB in the expected operation frequency band.

Analysis of microstrip coupled line based data signal and energy hybrid receiver

Abstract: This paper develops an original circuit theory of energy and data transition. The modelling of signal and energy hybrid receiver (SEHR) is developed. The SEHR topology is described in function of t...

Synthesis and experimentation of voltage compressor and decompressor with active circuit

Abstract: This paper introduces an innovative circuit theory of analog voltage compressor (AVC) and decompressor (AVD). This electronic function can also be assumed as an analog voltage converter. Analytically, it acts as power function synthesizer topology designed with an analog nonlinear circuit. The AVC/AVD topologies are based on an operational amplifier associated with resistor and non-linear diode components. Given the positive parameter a > 0, the main x-y characteristic of the AVC/AVD is formulated by y = xa for the input and output x and y, respectively. The synthesis formulas allowing to determine the AVC/AVD parameters as a function of a are established. To validate the original AVC/AVD concept, static and dynamic simulations and experimentations with a proof-of-concept circuit using operational amplifier UA741 are carried out. As expected, well correlated x1/2-AVC and x2-AVD characteristics are realized with the static testing for the voltage range varied from 0 to 9-V and 0 to 3-V for AVC and AVD circuits, respectively. The simulation and experimentation of dynamic test results are in good agreement for the sine wave voltages with frequency varied from DC to 1-kHz. The simulated and experimental results confirm the relevance of the developed compressor/decompressor analog circuit. The AVC/AVD functions for instrumentation system applications can be potentially applied to the amplitude matching especially for digital systems.

Similarity and Dimensional Methods in 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

Lectures on Theoretical Physics

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.)

Harvesting Water Drop Energy by 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.