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.

Anticipating Actuator Arbitrary Action With a Low-Pass Negative Group Delay Function

Abstract: This article investigates the feasibility of anticipating arbitrary signals from mechanical actuators. The anticipator originally operates with a low-pass negative group delay (NGD) function. The properties that enable NGD active topology to realize signal anticipation are analytically described. The NGD design and synthesis method as a function of the operating signal bandwidth is established. A real-time demonstration of the motion anticipation is originally performed with a rotating tunable resistor. Second-order motion angle anticipations are realized by completely considering the arbitrary waveform signals. The relevance of the motion anticipation is confirmed with more than a correlation coefficient between the NGD input and output signals that is more than 90%. Innovative real-time predictions of approximately −0.3 s are demonstrated. The present study indicates potential industrial applications of the NGD function in anomaly detections, future smart engines, and smart factories.

E-field extraction from Hx- and Hy- near field values by using plane wave spectrum method

Abstract: This paper deals with a technique for calculating the 3D E -field components knowing only the two components ( H x and H y ) of the H -field in near-zone. The originality of the under study technique lies on the possibility to take into account the evanescent wave influences. The presented E -field extraction process is based on the exploitation of the Maxwell-Ampere relation combined with the plane wave spectrum (PWS) method. The efficiency of the proposed technique is evidenced by comparing the E -field deduced from H -field and the own E -field radiated by the association of electrical- and also magnetic- elementary dipoles in different configurations by using Matlab text programming environment. In addition, as a concrete demonstrator, the concept was also validated with the computation of EM-wave radiated by an open-end microstrip transmission line. As result of comparison, very good agreement between the exact E -field and that one extracted from the H -field was realized by considering the near-field scanned at the height, z = 5 mm and 8 mm above the under test structure at the operating frequency, f = 1 GHz. The presented technique can simplify the difficulties about the E -near-field measurement in EMC applications.

Application of Near-Field Emission Processing for Microwave Circuits under Ultra-Short Duration Perturbations

Abstract: This paper is dealing with a time-frequency modeling method of electromagnetic (EM) near-field (NF) radiated by electronic devices excited by transient pulse signals. The model developed enables to calculate the EM NF maps at different distances from the given device and also the synthesis of radiation sources enabling to reproduce the field maps. The method proposed is based on the ultra wide band (UWB) frequency model of EM NF maps. The number of EM NF maps can be reduced by considering an innovative algorithm in order to establish simply the dipole model. Then, the transient model can be realized by considering the convolution between the transient excitation signals and the dipole-array model. The method proposed was validated by a standard 3D EM tool with a planar microstrip device excited by microwave signal modulating 1.25-GHz-carrier with 0.5-GHz-bandwidth. As expected, good correlation is found between results from simulation and the investigated modelling method. The method introduced in this paper is particularly useful for the investigation of time-domain emissions for EMC applications by considering transient EM interferences (EMIs).

0IO-Shape PCB Trace Negative Group-Delay Analysis

Abstract: This paper elaborates a negative group delay (NGD) analysis of 0IO-shape printed circuit board (PCB) traces. This circuit topology is originally implemented with a tri-coupled line (3CL) six-port element with the lateral side connected through lossy transmission lines (TLs). After description of the electrical equivalent diagram, the S-matrix model is established. The group delay (GD) is formulated from the transmission coefficient as a function of the 0IO topological parameters. The effectiveness of the GD modelling is verified with a microstrip circuit proof-of-concept (POC). Simulations and measurements, which are in good agreement, confirm the dual-band bandpass NGD behavior of the 0IO POC. The fabricated prototype generates NGD levels better than −1 ns at NGD center frequencies of about 2.2 GHz and 3 GHz. In addition, to this good NGD performance, the 0IO POC operates with a low insertion loss better than 2.5 dB and reflection losses better than 12 dB in the NGD bandwidths.

All-Pass Negative Group Delay Function With Transmission Line Feedback Topology

Abstract: A novel circuit theory of all-pass Negative group delay (NGD) function is investigated. The NGD function is implemented with unity direct chain feedback (UDCF) system. The active circuit is built with an operational amplifier in feedback with a lossy transmission line (TL). The UDCF topology S-parameter model is established versus TL parameters. The NGD analysis is elaborated from the frequency dependent transmission coefficient. The NGD behavior characterization is developed. The synthesis method allowing to determine the UDCF topology parameters in function of the targeted NGD values, gain and reflection coefficient is formulated. The all-pass NGD function is validated with a proof-of-concept (POC) design. Frequency and time domain simulations confirm the feasibility of the innovative all-pass NGD function. With S-parameter analysis, it was shown that the UDCF circuit exhibits NGD up to -7-ns with gain more than 0-dB and reflection coefficient -20-dB. More importantly, time-domain analysis illustrates how the transient tested voltage outputs can be in advance compared to the input.

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.