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.

Experimental investigation on the power electronic transistor parameters influence to the near-field radiation for the emc applications

Abstract: With the increases of the module integration density and complexity in electrical and power electronic systems, serious problems related to electromagnetic interference (EMI) and electromagnetic compatibility (EMC) can occur. For the safety, these disturbing efiects must be considered during the electronic equipment design process. One of the concerns on EMC problems is induced by unintentional near-fleld (NF) radiations. The modeling and measurement of EM NF radiations is one of the bottlenecks which must be overcome by electronic engineers. To predict the unwanted difierent misbehaviors caused by the EM radiation, NF test benches for the reconstitution of scanning maps at some millimeters of electrical/electronic circuits under test were developed at the IRSEEM laboratory. Due to the di-culty of the design with commercial simulators, the prediction of EM NF emitted by active electronic systems which are usually based on the use of transistors necessitates more relevant and reliable analysis techniques. For this reason, the main focus of this article is on the experimental analysis of EM NF radiated by an MOSFET transistor with changing electrical parameters. Descriptions of the experimental test bench for the EM map scan of transistors radiation are provided. This experimental setup allows not only to detect the EM NF emission but also to analyze the in∞uence of the excitation signal parameters

Application of a hybrid model for the susceptibility of complex form metallic wires perturbed by em near-field radiated by electronic structures

Abstract: A modeling of the metallic wires susceptibility facing to the disturbances caused by electromagnetic (EM) near-fleld (NF) radiated by electronic structures in radio frequencies (RF) is introduced by using a hybrid method. This latter is based on the use of the given EM-data calculated or determined from the standard computation tools associated with basic analytical methods expressing the coupling voltages at the victim wire extremities and the EM-NF radiations. In difierence to the classical methods based on the far-fleld radiations, the main beneflt of this method lies on the possibility to take into account the evanescent waves from the disturbing elements. The basic principle illustrating the hybrid method principle is explained. To verify the relevance of the method proposed, we consider a metallic wire having cm-length above the ground plane disturbed by the EM-near-waves from the electronic circuits in proximity. For that, we model the EM radiation of the disturbing electronic circuits and then, apply the hybrid method to evaluate the coupling voltages induced through the wires. By considering the radiations around hundreds MHz, we demonstrate that the hybrid method proposed enables us to generate voltages in good agreement with the simulations performed with the commercial tools. Two types of realistic conflgurations are studied. First, with a microstrip loop circuit radiating at about 0.7GHz, we calculated induced voltages at the extremities of the structures. Then, the same analysis was made with a 3D-model coil self for the large band from 0.1GHz to 0.5GHz. The results are in good accordance between the terminal voltages of

High-pass NGD characterization of resistive-inductive network based low-frequency circuit

Abstract: The purpose of this paper is to provide the high-pass (HP) negative group delay (NGD) circuit based (RL) network. Synthesis and experimental investigation of HP-NGD circuit are developed.,The research work methodology is organized in three phases. The definition of the HP-NGD ideal specifications is introduced. The synthesis method allowing to determine the RL elements is developed. The validation results are discussed with comparison between the calculated model, simulation and measurement.,This paper shows a validation of the HP-NGD theory with responses confirming NGD optimal frequency, value and attenuation of about (9 kHz, −1.12 µs, −1.64 dB) and (21 kHz, −0.92 µs, −4.81 dB) are measured. The tested circuits have experimented NGD cut-off frequencies around 5 and 11.7 kHz.,The validity of the HP-NGD topology depends on the coil self-inductance resonance. The HP-NGD effect is susceptible to be penalized by the parasitic elements of the self.,The NGD circuit is usefully exploited in the electronic and communication system to reduce the undesired delay effect context. The NGD can be used to compensate the delay in any electronic devices and system.,Applications based on the NGD technology will be helpful in the communication, transportation and security research fields by reducing the delay inherent to any electronic circuit.,The originality of the paper concerns the synthesis formulations of the RL elements in function of the expected HP-NGD optimal frequency, value and attenuation. In addition, an original measurement technique of HP-NGD is also introduced.

Assessment of 50%-Propagation-Delay for Cascaded PCB Non-Linear Interconnect Lines for the High-Rate Signal Integrity Analysis

Abstract: This paper presents an enlarged study about the 50-% propagation-time assessment of cascaded transmission lines (TLs). First and foremost, the accurate modeling and measurement technique of signal integrity (SI) for high-rate microelectronic interconnection is recalled. This model is based on the reduced transfer function extracted from the electromagnetic (EM) behavior of the interconnect line RLCG-parameters. So, the transfer function established takes into account both the frequency dispersion effects and the different propagation modes. In addition, the transfer function includes also the load and source impedance effects. Then, the SI analysis is proposed for high-speed digital signals through the developed model. To validate the model understudy, a prototype of microstrip interconnection with w = 500 µm and length d = 33 mm was designed, simulated, fabricated and tested. Then, comparisons between the frequency and time domain results from the model and from measurements are performed. As expected, good agreement between the S-parameters form measurements and the model proposed is obtained from DC to 8 GHz. Furthermore, a de-embedding method enabling to cancel out the connectors and the probe effects are also presented. In addition, an innovative time-domain characterization is proposed in order to validate the concept with a 2.38 Gbit/s-input data signal. Afterwards, the 50-% propagation-time assessment problem is clearly exposed. Consequently an extracting theory of this propagation-time with first order RC-circuits is presented. Finally, to show the relevance of this calculation, propagation-time simulations and an application to signal integrity issues are offered.

Bandpass Negative Group Delay Theory of Fully Capacitive Δ-Network

Abstract: A particularly original negative group delay (NGD) theory of $\Delta $ -topology is developed in the present paper. The NGD three-port topology is a passive circuit purely constituted by capacitors network. The model of the proposed $\Delta $ -topology impedance 3-D matrix is analytically established in function of the capacitor elements. Then, the S-matrix model is derived by using the Y-to-S transform. By considering the S-matrix frequency responses, a bandpass (BP) NGD analysis of the capacitive $\Delta $ -topology is originally elaborated. It is theoretically demonstrated that the passive $\Delta $ -topology is susceptible to behave as a BP NGD circuit under an analytical condition between the constituting capacitor values. The design feasibility of the BP NGD function is experimentally verified with lumped capacitor components-based $\Delta $ -circuit proof of concept. An electronic circuit board constituted by purely capacitive-network $\Delta $ -circuit is fabricated as an original $\Delta $ -circuit prototype. The tested board is constituted by arbitrary chosen capacitors, 100 nF, 10 nF and 0.1 nF. As expected, the calculation, simulation and measurement results, which are in very good agreement, confirm the BP NGD behavior. It is observed from measurement that it generates NGD of about −18.1 ns at a frequency of about 0.55 MHz and, lower and upper cut-off frequencies of about 0.33 MHz and 1.71 MHz. It is noteworthy that the transmission and reflection coefficients at very low frequency are independent of the capacitor values and analytically equal to 2/3 and 1/3, respectively.

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.