Multidomain Pseudospectral Time-domain Method Research Articles

Scattering of Object Buried below Random Rough Surface—A Monte Carlo Pseudospectral Time-Domain Approach

Absract This article presents a numerical technique combining the multi-domain pseudospectral time-domain method and the Monte Carlo method for determining the scattering of an object buried below a random rough surface separating two half-spaces. The numerical technique is employed to determine the scattering of a cylinder buried below a random rough surface of finite length under various conditions. Sample numerical results are presented, validated, and analyzed. The results illustrate the significant impact of the roughness of the surface and the electromagnetic properties of the lower half-space on the scattered signature of the buried cylinder.

Applications of the multidomain pseudospectral time-domain algorithm for waveguide structures

The authors have analysed the complex waveguide structures by the multidomain pseudospectral time-domain (MPSTD) algorithm, and discussed the design of a filtering procedure through improving the stability of the MPSTD method for the corner singularities. These numerical results of the MPSTD method have shown an excellent agreement with those results of the analytical solution and the traditional finite-difference time-domain method for the resonant frequencies of the waveguide structures. It is evident that the MPSTD method can achieve high efficiency and accuracy when we use to analyse inhomogeneous media and curved objects.

Multidomain Pseudospectral Time Domain Algorithm Using a Symplectic Integrator

The novel multidomain pseudospectral time domain method based on a symplectic integrator scheme is presented in this paper. A symplectic integrator scheme is a decomposition of the exponential operator or a general propagation technique. The scheme is nondissipative and does not require additional memory for temporary storage of data for the internal stages. The good performance of the scheme is demonstrated by numerical examples

Multidomain pseudospectral time‐domain method for computation of electromagnetic scattering by bodies of revolution

AbstractWe present a multidomain pseudospectral method using cylindrical and spherical coordinates for the accurate and efficient time‐domain computation of scattering by bodies of revolution (BOR). In the BOR formulation of Maxwell's equations, the Fourier collocation method is utilized in the azimuthal direction and the Chebyshev collocation method in the other directions. Using the complex‐coordinate‐stretching approach, the strongly well‐posed perfectly matched layer (PML) formulations are derived in cylindrical and spherical coordinates. A comparison of the results obtained using the multidomain pseudospectral method and those using the finite‐difference time‐domain (FDTD) method clearly illustrates the superiority of the algorithm developed in this paper. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 92–96, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21091

MULTIDOMAIN PSEUDOSPECTRAL TIME-DOMAIN (PSTD) METHOD FOR ACOUSTIC WAVES IN LOSSY MEDIA

A multidomain pseudospectral time-domain (PSTD) method is developed for acoustic wave equations in lossy media. The method is based on the spectral derivative operator approximated by Chebyshev Lagrange polynomials. In this multidomain scheme, the computational domain is decomposed into a set of subdomains conformal to the problem geometry. Each curved subdomain is then mapped onto a cube in the curvilinear coordinates so that a tensor-product Chebyshev grid can be utilized without the staircasing error. An unsplit-field, well-posed PML is developed as the absorbing boundary condition. The algorithm is validated by analytical solutions. The numerical solutions show that this algorithm is efficient for simulating acoustic wave phenomena in the presence of complex objects in inhomogeneous media. To our knowledge, the multidomain PSTD method for acoustics is a new development in three dimensions, although in two dimensions the method can be made equivalent to the two-dimensional method in electromagnetics.

A Multidomain PSTD Method for 3D Elastic Wave Equations

A 3D multidomain pseudospectral time-domain method is developed for elastic wave equations. The method is based on the spectral derivative operator approximated by Chebyshev or Lagrange polynomials. Unlike the Fourier method that assumes periodic boundary conditions, the Chebyshev pseudospectral method allows for the incorporation of various boundary conditions (such as the free surface boundary condition) into the numerical scheme. In this multidomain scheme, the computational domain is decomposed into a set of subdomains conformal to the problem geometry. Each curved subdomain is then mapped onto a cube in the curvilinear coordinates so that a tensor-product Chebyshev grid can be utilized without the staircasing error. An unsplit-field perfectly matched layer is developed as the absorbing boundary condition. Numerical examples show that this scheme is efficient for simulating elastic waves phenomena in the presence of complex objects. The method is found to be significantly more efficient than the finite-difference time-domain method in terms of memory and run-time requirements.