			Home About us Contact

Far-field Data (far-field + data)

Distribution by Scientific Domains

Engineering	75%

Selected Abstracts

Source localization using electric and magnetic point dipoles with modified genetic algorithm

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 4 2009
Päivi K. Koivisto
Abstract A method to reconstruct the source current from far-field data in terms of electric and magnetic point dipoles is described. The inverse problem of solving the source from a known electromagnetic far-field pattern is carried out by a combination of genetic algorithm and local optimizers. The source is modelled by a small number of point dipoles, the locations, amplitudes and types of which are determined by minimizing the difference between the field of the ensemble and the targeted pattern. Uniqueness is ensured by limiting the number of dipoles together with an appropriately weighted minimum energy condition. A general description of the method applicable to antenna analysis and synthesis is given and three examples of its practical use are presented. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Comparison of image reconstruction by using near-field and far-field data for an imperfect conductor

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2001
Chien-Ching Chiu
Abstract Image reconstruction by using near-field and far-field data for an imperfectly conducting cylinder is investigated. A conducting cylinder of unknown shape and conductivity scatters the incident wave in free space and the scattered near and far fields are measured. By using measured fields, the imaging problem is reformulated into an optimization problem and solved by the genetic algorithm. Numerical results show that the convergence speed and final reconstructed results by using near-field data are better than those obtained by using far-field data. This work provides both comparative and quantitative information. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 69,73, 2001. [source]

Reconstructing small perturbations of scatterers from electric or acoustic far-field measurements

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 11 2008
Mikyoung Lim
Abstract In this paper, we consider the problem of determining the boundary perturbations of an object from far-field electric or acoustic measurements. Assuming that the unknown scatterer boundary is a small perturbation of a circle, we develop a linearized relationship between the far-field data and the shape of the object. This relationship is used to find the Fourier coefficients of the perturbation of the shape. Copyright © 2008 John Wiley & Sons, Ltd. [source]