Search results for "circuits"
showing 10 items of 358 documents
Video Streaming Distribution in VANETs
2011
Streaming applications will rapidly develop and contribute a significant amount of traffic in the near future. A problem, scarcely addressed so far, is how to distribute video streaming traffic from one source to all nodes in an urban vehicular network. This problem significantly differs from previous work on broadcast and multicast in ad hoc networks because of the highly dynamic topology of vehicular networks and the strict delay requirements of streaming applications. We present a solution for intervehicular communications, called Streaming Urban Video (SUV), that 1) is fully distributed and dynamically adapts to topology changes, and 2) leverages the characteristics of streaming applica…
Implementation of compact VLSI FitzHugh-Nagumo neurons
2008
In this paper we show a low power and very compact VLSI implementation of a FitzHugh-Nagumo neuron for large network implementations. The circuit consists of only 17 small transistors and two capacitors and consumes less than 23 muW. It is composed of a nonlinear resistor and a lossy active inductor. We demonstrate that a simple low Q active inductor can be used instead of a complex one because the parasitic series resistor can be easily embedded to the FitzHugh-Nagumo model. We also perform a statistical analysis to check the robustness of the circuit against mismatch.
Realistic model of compact VLSI FitzHugh–Nagumo oscillators
2013
In this article, we present a compact analogue VLSI implementation of the FitzHugh–Nagumo neuron model, intended to model large-scale, biologically plausible, oscillator networks. As the model requires a series resistor and a parallel capacitor with the inductor, which is the most complex part of the design, it is possible to greatly simplify the active inductor implementation compared to other implementations of this device as typically found in filters by allowing appreciable, but well modelled, nonidealities. We model and obtain the parameters of the inductor nonideal model as an inductance in series with a parasitic resistor and a second order low-pass filter with a large cut-off freque…
Fault Emulation for Dependability Evaluation of VLSI Systems
2008
Advances in semiconductor technologies are greatly increasing the likelihood of fault occurrence in deep-submicrometer manufactured VLSI systems. The dependability assessment of VLSI critical systems is a hot topic that requires further research. Field-programmable gate arrays (FPGAs) have been recently pro posed as a means for speeding-up the fault injection process in VLSI systems models (fault emulation) and for reducing the cost of fixing any error due to their applicability in the first steps of the development cycle. However, only a reduced set of fault models, mainly stuck-at and bit-flip, have been considered in fault emulation approaches. This paper describes the procedures to inje…
A VLSI for deskewing and fault tolerance in LVDS links
2005
The device presented at this work is a switch implemented in a 0.35 mum CMOS process for compensating the skew which affects parallel data signal transmissions and for providing fault tolerance in large scale scalable systems, for instance used in trigger farms for high energy physics experiments. The SWIFT chip (SWItch for Fault Tolerance) is part of a cluster built around commercially components which has been inspired by the LHCb experiment. The skew is extremely important because it directly affects the sample window available to the receiver logic and either forces to use quality and expensive cables in order to minimize its effects or reduces the maximum signal transmission range or d…
Creep Modeling with Time-Dependent Damping Parameters in Piezoelectric Actuators
2019
This paper develops a creep model based on the Kelvin-Voigt model with time varying damping parameters. In the piezoelectric actuators, the creep phenomenon is an important issue in precise positioning applications as well as the hysteresis property. It is well-known that the creep effect can be represented by a series connection of a number of Kelvin-Voigt elements as a viscoelastic model. In the motion for the continuous stepwise positioning, however, the creep shape is different for each response. Since the phenomenon can be captured as temporal creep relaxation, time-dependent damping parameters are introduced to improve the reproducibility of the creep for the various motion. On the ot…
Resonance phenomena in a nonlinear neuronal circuit
2015
International audience; We characterizes a nonlinear circuit driven by a bichromatic excitation,that is the sum of two sinusoidal waves with different frequencies f1 and f2 suchthat f2 > f1. Our experiments are confirmed by a numerical analysis of the systemresponse obtained by solving numerically the differential equations which rule thecircuit voltages. Especially, we highlight that the response of the system at the lowfrequency can be optimized by the amplitude of the high frequency. By revisiting thiswell known vibrational resonance effect in the whole amplitude frequency parametricplane, we show experimentally and numerically that a much better resonance can beachieved when the two fre…
Performance analysis and comparison of symmetrical and asymmetrical configurations of evanescent mode ridge waveguide filters
2009
[1] In this paper, the trade-offs between out-of-band performance, filter length, power-handling capability, and insertion loss of both symmetrical and asymmetrical evanescent mode ridge rectangular waveguide filters are investigated. As a result, clear design methodologies for optimizing such performances are proposed. The developed methodologies are then applied to design several evanescent mode filters, and a complete performance analysis of the symmetrical and asymmetrical structures is performed. From the performance analysis results, the designer can choose the more appropriate filter topology and design strategy to satisfy the prescribed specifications.
Critical Influence of Dielectric Sensitive Material and Manufactured Process in Microwave Gas-Sensing: Application of Ammonia Detection with an Inter…
2020
In this paper, authors propose a study on microwave gas sensors and the influence of critical key parameters such as the sensitive material and the circuit conception process. This work aims to determine the influence of these parameters on the quality of the final response of the microwave gas sensor. The fixed geometry of the sensor is a microstrip interdigital capacitor coated with a sensitive layer excited with two 50 Ω SMA ports. The sensitive material has been chosen in order to interact with the target gas: ammonia. Indeed, this gas interacts with phthalocyanine and metal oxides like hematite, TiO2. To explore the effect of the circuit manufacturing process, three series of samples a…
Design and Characterization of Automated Color Sensors System
2014
International audience; The paper presents a color sensor system that can process light reflected from a surface and produce a digital output representing the color of the surface. The end-user interface circuit requires only a 3-bit pseudo flash analog-to-digital converter (ADC) in place of the conventional/typical design comprising ADC, digital signal processor and memory. For scalability and compactness, the ADC was designed such that only two comparators were required regardless of the number of color/wavelength to be identified. The complete system design has been implemented in hardware (bread board) and fully characterized. The ADC achieved less than 0.1 LSB for both INL and DNL. The…