Search results for "time-domain"

showing 10 items of 63 documents

EMI Analysis in Electrical Drives under Lightning Surge Conditions

2012

In this paper, a complete model of a power drive system including the earth electrodes is proposed to evaluate electromagnetic conducted interference due to lightning pulses. Circuit model of a power drive system is joined with a full-wave approach for the simulation of the time behavior of the grounding system. The proposed model enables to predict the electromagnetic conducted interference generated in the power drive system when lightning conditions involve the earth electrodes.

Conducted electromagnetic interferenceEngineeringbusiness.industryGroundElectromagnetic compatibilityElectrical engineeringElectromagnetic interference (EMI) electromagnetic transients finite-difference time-domain method induction motor drives lightning protection moments method.Condensed Matter PhysicsEarthing systemLightning arresterLightningAtomic and Molecular Physics and OpticsElectromagnetic interferencePhysics::GeophysicsSettore ING-IND/31 - ElettrotecnicaHardware_GENERALPhysics::Plasma PhysicsEMIElectronic engineeringElectrical and Electronic Engineeringbusiness
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A wideband THz Time Domain Spectroscopy table-top system based on ultrafast pulsed laser: Model and experiments

2014

We present an analytical model carefully describing the time-frequency behavior of all the stages composing our whole Terahertz Time Domain Spectroscopy laser based system, from the THz pulses generation via Optical Rectification, to their detection through Electro-Optic Sampling technique, by way of diffraction, collecting and focusing effects. In order to prove the effectiveness of our work, we report on the comparison among the experimental waveforms and the simulation results.

DiffractionMaterials scienceTerahertz radiationbusiness.industryLaserlaw.inventionTerahertz spectroscopy and technologyOptical rectificationOpticslawWidebandbusinessTerahertz time-domain spectroscopyUltrashort pulse2014 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)
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Sub-wavelength imaging of light confinement and propagation in SOI based photonic crystal devices

2006

A light source is coupled into photonic crystal devices and a near field optical probe is used to observe the electromagnetic field propagation and distribution at a sub-wavelength scale. Bloch modes are clearly observed.

Electromagnetic fieldMaterials sciencebusiness.industryPhotonic integrated circuitNear-field opticsFinite-difference time-domain methodPhysics::OpticsSilicon on insulatorNear and far fieldOpticsOptoelectronicsNear-field scanning optical microscopebusinessPhotonic crystal
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A Smoothed Particle Interpolation Scheme for Transient Electromagnetic Simulation

2006

In this paper, the fundamentals of a mesh-free particle numerical method for electromagnetic transient simulation are presented. The smoothed particle interpolation methodology is used by considering the particles as interpolation points in which the electromagnetic field components are computed. The particles can be arbitrarily placed in the problem domain: No regular grid, nor connectivity laws among the particles, have to be initially stated. Thus, the particles can be thickened only in distinct confined areas, where the electromagnetic field rapidly varies or in those regions in which objects of complex shape have to be simulated. Maxwell’s equations with the assigned boundary and initi…

Electromagnetic fieldPhysicsElectromagnetic (EM) transient analysiNumerical analysisMesh-free numerical techniqueSPHMathematical analysisFinite-difference time-domain methodNumerical MethodElectronic Optical and Magnetic MaterialsRegular gridsymbols.namesakeSmoothed particle interpolationSettore MAT/08 - Analisi NumericaSettore ING-IND/31 - ElettrotecnicaClassical mechanicsMaxwell's equationsElectromagnetismsymbolsParticleElectrical and Electronic EngineeringInterpolation
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FDTD simulation for electromagnetic radiated emissions in 42 V vehicle electrical systems

2005

In this paper a full 3D approach, based on finite difference time domain method, is used to predict the electromagnetic radiated emissions from 42 V vehicle electrical loads. An experimental set-up has been arranged on purpose. A comparative analysis among measured and computed results is performed. The good agreement obtained among simulated and measured data enables to validate the numerical scheme. The proposed methodology contributes to predict electromagnetic emissions in the automotive environment since the design stage. Moreover, the proposed numerical tool can be used to define, for new vehicle electrical architectures, low cost test methods for electromagnetic compatibility and sui…

EngineeringDesign stagebusiness.industryFDTDAutomotive industryElectromagnetic compatibilityFinite-difference time-domain methodTransmission-line matrix methodComputer simulationElectric vehicleElectromagnetic wave emissionAutomotive engineeringAutomotive electronicsAutomotive engineeringFinite difference time domain analysisSettore ING-IND/31 - ElettrotecnicaElectrical engineeringTime domain analysiElectronic engineeringComputational electromagneticselectromagnetic radiated emissionbusinessvehicular electrical systemElectric load
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Finite-Difference Time-Domain Simulation of Tower and Grounding Subjected to Lightning

2015

In this paper the behavior of a tower and its grounding system, subjected to a lightning, is faced. Finite difference time domain (FDTD) method has been chosen in order to study the non-linear time domain behavior of the system. The electromagnetic problem has been described by using two type of first order time derivative equations: Maxwell's equations and Telegraph equations. Aim of this work is to evaluate the possibility of a flashover between tower and power line, by considering different cases of study.

EngineeringGroundbusiness.industryMathematical analysisElectrical engineeringFinite-difference time-domain methodSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciEarthing systemLightningPower (physics)Settore ING-IND/31 - Elettrotecnicalightning grounding towerTime derivativeTime domainbusinessTower
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<title>Control and measuring buses with amplitude fiber optical sensors</title>

2004

This paper presents controlling-measuring buses (linear and quasi-linear) using amplitude properties of fiber-optics and fiber-optical sensors of typical and/or special construction. It refers to linear sensors and commonly used measuring OTDR method, as wel as to realizations with linear binary sensors in transmission networks. Presented advantages and parameters of such measuring structures. Presented main area of application buses and practical realizations, regarding typical needs in industrial measurements, points out technical and economical advantages, in opposition to difficult and expensive (but more accurate) technology of measuring networks based on polarization and interfering m…

EngineeringOptical fiberbusiness.industryOptical engineeringIntegrated circuitOptical time-domain reflectometerlaw.inventionSensor arraylawFiber optic sensorControl systemElectronic engineeringbusinessWireless sensor networkSPIE Proceedings
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Efficient FDTD analysis of discontinuities in a square coaxial waveguide

1996

Engineeringbusiness.industryAcousticsFinite-difference time-domain methodElectronic engineeringCoaxial waveguidesElectrical and Electronic EngineeringClassification of discontinuitiesCondensed Matter PhysicsbusinessAtomic and Molecular Physics and OpticsSquare (algebra)Electronic Optical and Magnetic MaterialsMicrowave and Optical Technology Letters
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A low-cost compact uniplanar Quasi–Yagi printed antenna

2008

A low cost directive uniplanar broadband printed Quasi–Yagi antenna design is presented. As a particular realization, some prototypes have been designed to operate in the 2.45 GHz band. They have been then modeled, fabricated onto standard printed circuit dielectric substrate and tested successfully. For the design and the modeling processes, we have make use of FDTD based in-house developed algorithms. The obtained bandwidth is, for all the considered cases, better than 15%. The main radiation characteristics are 2–5.5 dBi gain, depending on the number of director elements, and better than 25 dB front-to-back ratio. Overall antenna size was, in any case lesser than 1 λ × 0.5 λ. © 2008 Wile…

Engineeringbusiness.industryAntenna designBandwidth (signal processing)Electrical engineeringFinite-difference time-domain methodDielectric substrateCondensed Matter PhysicsDirectivityAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsPrinted circuit boardBroadbandElectrical and Electronic EngineeringbusinessMicrowaveMicrowave and Optical Technology Letters
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Design of Yagi-like printed antennas for WLAN applications

2007

A directive broadband printed Yagi-like antenna design is presented. We have focused on the 2.45 GHz WLAN band, at which some designs have been carried out. For the design and the modelling processes, we made use of FDTD based in-house developed algorithms. Some selected prototypes have then been fabricated onto a low-cost printed circuit board dielectric substrate and tested successfully. Bandwidths higher than 10% and moderate to high (>7 dBi) gains can be obtained this way. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2174–2178, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22655

Engineeringbusiness.industryAntenna designFinite-difference time-domain methodElectrical engineeringDielectric substrateCondensed Matter PhysicsDirectivityAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsPrinted circuit boardBroadbandElectronic engineeringElectrical and Electronic EngineeringbusinessMicrowaveMicrowave and Optical Technology Letters
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