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Section 6: Electromagnetic Field Modeling of Diamond CVD Reactors
Published in Mark A. Prelas, Galina Popovici, Louis K. Bigelow, Handbook of Industrial Diamonds and Diamond Films, 2018
and since ∇·(∇ x E)= 0 it can be concluded that ∇·B = constant. So the solution of (4) is an initial condition for the time domain solution of (1). Therefore, the solution of Maxwell equations can be done by solving equations (1), (2) and (3) in the time domain. A simplification often made for this solution is that of solving the high-frequency behavior, given primarily by (1) and (2) which have time derivative terms, separately from the low frequency or dc behavior. The time domain method used to solve (1) and (2) is called the finite-difference time-domain method (FDTD). The FDTD technique was first proposed by Yee [Yee 1966] in 1966 to solve the interaction of electromagnetic waves with two-dimensional, isotropic material. Recent studies used the FDTD method for the solution of three-dimensional scattering problems, lossy dielectric materials, resonant cavities, thin plates and wires, and bioelectromagnetic dosimetry problems [Taflove and Brodwin 1975], [Mur 1981] and [Gothard et al. 1994]. The FDTD technique has also been applied to study the electromagnetic field interactions with plasma discharges [Grotjohn 1992], [Grotjohn et al. 1994], [Tan and Grotjohn 1994], [Tan and Grotjohn 1995] and [Hunsberger et al. 1992]. Overall, the FDTD method has the advantage of ease of implementation for complicated geometries, because spatially varying dielectric and conductivity parameters can be assigned using grid points.
Computational Biophotonics
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
As a rule, the larger the overall length scale of the problem, the coarser the level of detail that are considered by a simulation. For example, while finite-difference time-domain method can be and is widely used to model single scattering with the spatial distribution of refractive index being modeled with nanoscale precision, in most cases, its computational complexity allows FDTD to be used with microscopic objects only. The pseudospectral time-domain method, on the other hand, can model light transport with macroscopic volumes of tissue (e.g., hundreds of microns), but at the cost of losing nanoscale sensitivity of FDTD; PSTD models spatial distribution of refractive index with details on the order of half wavelengths, that is, hundreds of nanometers.
Electromagnetic Fields in Transformers: Theory and Computations
Published in S.V. Kulkarni, S.A. Khaparde, Transformer Engineering, 2017
The finite difference time domain method (FDTD) is an extension of FDM for simulation of high frequency electromagnetic phenomena. One may wonder about its applicability to transformers, a low frequency device. It can be used successfully for the simulation and diagnostics of partial discharges (PD) propagating in the form of high frequency electromagnetic waves. The theory and implementation aspects of the method for PD diagnostics are elaborated in Section 14.3. The method is conceptually simple as compared to the other methods (FEM and MOM) that can be used for the purpose.
A Flexible Multiband Antenna for Biomedical Telemetry
Published in IETE Journal of Research, 2023
Abdullah Al-Sehemi, Ahmed Al-Ghamdi, Nikolay Dishovsky, Gabriela Atanasova, Nikolay Atanasov
Design and analysis of the antenna were carried out using the full-wave electromagnetic software package xFDTD (xFDTD, Remcom Inc., State College, PA, USA) based on the finite-difference time-domain method (FDTD). The FDTD method was chosen because it is widely used for the analysis, optimization and synthesis of antennas in the vicinity of human body or head and it is stable and accurate, does not require enormous computational recourses [5]. All numerical calculations were performed with a non-uniform cubic-cell mesh having fine-size cells of 0.5 mm and coarse-size cells of 3 mm. The perfectly matched layer (7 layers) absorbing boundary condition was used to absorb the fields traveling away from the interior of the mesh. The 12-field components approach was selected to calculate SAR.