12,890 research outputs found
Conical cut radar cross section calculations for a thin, perfectly conducting plate
Radar Cross Section (RCS) calculations for flat, perfectly conducting plates are readily available through the use of conventional frequency domain techniques such as the Method of Moments. However, if time domain scattering or wideband frequency domain results are desired, then the Finite Difference Time Domain (FDTD) technique is a suitable choice. In this paper, we present the application of the Finite Difference Time Domain (FDTD) technique to the problem of electromagnetic scattering and RCS calculations from a thin, perfectly conducting plate for a conical cut in the scattering angle phi. RCS calculations versus angle phi will be presented and discussed
FDTD modeling of thin impedance sheets
Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods
Numerical study of light correlations in a random medium close to Anderson localization threshold
We applied finite difference time domain (FDTD) algorithm to the study of
field and intensity correlations in random media. Close to the onset of
Anderson localization, we observe deviations of the correlation functions, in
both shape and magnitude, from those predicted by the diffusion theory.
Physical implications of the observed phenomena are discussed.Comment: 12 pages, 4 figures. to be published in Optics Letters 29, 917 - 919
(2004
An Approximate PML Applied to Cylindrical and Spherical Coordinate Sectors
This letter proposes an approximate perfectly matched layer (PML) that is applicable to cylindrical and spherical coordinate sectors. The proposed PML is based on complex coordinate stretching, which enables the truncation of finite-difference time-domain (FDTD) grids, not only at the ρ- and r-coordinates but also at the φ- and θ-coordinates. The absorption performance of the PML is demonstrated through numerical simulations
Theoretical study on dispersion compensation in air-core Bragg fibers
In a previous paper we developed a matrix theory that applies to any cylindrically symmetric fiber surrounded by Bragg cladding. Using this formalism, along with Finite Difference Time Domain (FDTD) simulations, we study the waveguide dispersion for the m = 1 mode in an air-core Bragg fiber and showed it is possible to achieve very large negative dispersion values (~ -20,000 ps/(nm.km)) with significantly reduced absorption loss and non-linear effects
Birefringent dispersive FDTD subgridding scheme
A novel 2D finite difference time domain (FDTD) subgridding method is proposed, only subject to the Courant limit of the coarse grid. By making mu or epsilon inside the subgrid dispersive, unconditional stability is induced at the cost of a sparse, implicit set of update equations. By only adding dispersion along preferential directions, it is possible to dramatically reduce the rank of the matrix equation that needs to be solved
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