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Spherical Waves (spherical + wave)

Distribution by Scientific Domains
Engineering80%

Selected Abstracts

Multi-region ADI DD-FDTD algorithm for the analysis of three-dimensional sparse multi-objects scattering problem

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1-2 2008
Feng Xu
In this paper, a multi-region domain decomposition finite-difference time-domain (DD-FDTD) algorithm is proposed and developed for the analysis of multiple-objects electromagnetic (EM) problems. A significant number of mesh nodes between objects are removed since only local meshes are generated for each object. All the separated sub-domains are interconnected by the use of a 3-D time-domain Green's function. The coupling between objects can be regarded as the equivalent spherical wave irradiations. Incident signals of the equivalent spherical waves are expressed as a spherical wave input field array according to the Huygens principle. The near-field to far-field transformation is introduced to obtain the equivalent spherical wave. Moreover, the alternating direction implicit FDTD (ADI-FDTD) scheme is applied to overcome the limit of the stability condition and increase the speed of the simulation. The new algorithm has been demonstrated and applied to solve typical 3-D multi-objects EM scattering problems. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Scattering relations for point-source excitation in chiral media

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 1 2006
Christodoulos Athanasiadis
Abstract A spherical electromagnetic wave propagating in a chiral medium is scattered by a bounded chiral obstacle which can have any of the usual properties. Reciprocity and general scattering theorems, relating the scattered fields due to scattering of waves from a point source put in any two different locations are established. Applying the general scattering theorem for appropriate locations and polarizations of the point source we prove an associated forward scattering theorem. Mixed scattering relations, relating the scattered fields due to a plane wave and the far-field patterns due to a spherical wave, are also established. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Multi-region ADI DD-FDTD algorithm for the analysis of three-dimensional sparse multi-objects scattering problem

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1-2 2008
Feng Xu
In this paper, a multi-region domain decomposition finite-difference time-domain (DD-FDTD) algorithm is proposed and developed for the analysis of multiple-objects electromagnetic (EM) problems. A significant number of mesh nodes between objects are removed since only local meshes are generated for each object. All the separated sub-domains are interconnected by the use of a 3-D time-domain Green's function. The coupling between objects can be regarded as the equivalent spherical wave irradiations. Incident signals of the equivalent spherical waves are expressed as a spherical wave input field array according to the Huygens principle. The near-field to far-field transformation is introduced to obtain the equivalent spherical wave. Moreover, the alternating direction implicit FDTD (ADI-FDTD) scheme is applied to overcome the limit of the stability condition and increase the speed of the simulation. The new algorithm has been demonstrated and applied to solve typical 3-D multi-objects EM scattering problems. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A new time domain solution for the multiple diffraction of spherical waves by an array of nonperfectly conducting wedges for UWB signals

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010
Peng Liu
Abstract A time domain (TD) solution for the analysis of multiple diffraction of spherical waves after an array of nonperfectly conducting wedges with different interior angles is presented. The proposed TD solution is based on the representation of the inverse Laplace transform of the corresponding frequency domain solution in closed form, as it is given by a hybrid of the uniform theory of diffraction (UTD)-physic optics (PO) solution. The new formulation, validated with the results from technical literature, does not need to incorporate the TD version of the higher-order diffraction coefficients and allows for the calculation of large number of wedges. It has the major advantage in terms of the mathematical complexity and computation efficiency when compared with other TD solutions. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1006,1008, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25094 [source]