Search results for "Finite-difference time-domain method"
showing 10 items of 39 documents
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…
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…
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.
Efficient FDTD analysis of discontinuities in a square coaxial waveguide
1996
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…
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
Full-wave FDTD design and analysis of wideband microstrip-to-waveguide transitions
2003
Wideband transitions are designed and analysed by using two different approaches of the finite-difference time-domain (FDTD) method, in combination with the theory of nonuniform transmission lines. These transitions consist of a ridged waveguide-based taper between a shielded microstrip and a standard X-band rectangular waveguide. In the first step, a full-wave 2D-FDTD scheme is used to calculate the dispersion characteristics, as well as the geometry dependence of the impedance in the double ridged waveguide. Once these design curves have been obtained, the stepped transmission line transformer theory is used to design the tapers. In a former step, the nonuniform 3D-FDTD technique is appli…
Calculation of the characteristic impedance of microstrips using a full-wave 2-D FDTD scheme
1997
The frequency dependence of the characteristic impedance of microstrip lines has been investigated by many authors using 3D-FDTD formulations. In the present letter, a two-dimensional FDTD scheme is used to calculate both the propagation constant and the characteristic impedance of the fundamental quasi-TEM mode in a microstrip which, in fact, is a hybrid mode. Because of the substantial reduction of computer resources required for the calculations, this method can be used as a design tool. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 16: 58–60, 1997.
Finite-Difference Time-Domain Simulation of Towers Cascade Under Lightning Surge Conditions
2015
In this paper, the simulation of towers cascade under lightning surge conditions is presented. Finite-difference time-domain method is used to solve both the Maxwell's and telegraph equations. Maxwell's equations and the time-domain resistivity model of Darveniza are used to simulate the nonlinear behavior of the grounding system. Telegraph equations are used to describe the propagation in the overhead lines. Multiple ionizations, on different grounding electrodes belonging to various towers, can be implemented simultaneously, without making assumptions on the shape of the ionized areas.
Evaluation of radiated EMI in 42 V vehicle electrical systems by FDTD simulation
2007
In this paper a full 3D numerical scheme, based on the finite difference time domain method, is used to predict the electromagnetic radiated interference generated by 42 V vehicle power electronic driven electrical loads. An experimental set-up has been arranged on purpose in order to validate the proposed simulation tool. To this aim, the features of a semi-anechoic electromagnetic chamber have been exploited in order to operate in a shielded test site for the measurement of near field radiated emissions. Two different three-dimensional geometrical configurations of realistic vehicle installations of the loads, are studied. A comparative analysis among measured and computed results is perf…