Summary
International Symposium on Antennas and Propagation
2008
Session Number:4B13
Session:
Number:4B13-3
Performance Improvement of a Reconstruction Algorithm in Electromagnetic Inverse Scattering Problem
Mitsuru Tanaka, Masahiko Sano, Atsushi Kusunoki,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
Electromagnetic chracterization of internal properties, size, shape, and location of a scattering object has been one of the most important and challenging topics in electromagnetics community due to its practical applications in biomedical diagnostics, nondestructive testing of materials, and detection of buried objects. In recent years, many inversion methods have been proposed to solve the inverse scattering problems [1]-[8]. It is the purpose of this paper to consider the performance improvement of an iterative inversion algorithm of reconstructing the relative permittivity of a lossy dielectric cylinder based on the multigrid optimization method. The object located in a homogeneous background medium is illuminated with multifrequency cylindrical electromagnetic waves in microwave region. A cost functional is de￣ned as the norm of a diRerence between the scattered electric ￣elds measured and calculated. Then the electromagnetic inverse scattering problem can be treated as an optimization problem where the contrast function is determined by minimizing the cost functional. We employ the multigrid optimization method to solve the optimization problem. This method is composed of the frequency-hopping technique with a weighting factor, the multigrid method with a V-cycle [9], and the conjugate gradient method [1]. Computer simulations are performed for a lossy and homogeneous dielectric circular cylinder to show the eRect of the weighting factor on the reconstruction accuracy.