Abstract
This article presents an acceleration technique for the fist calculation of the impedance matrix elements in the method of moments in the case of using characteristic basis functions (CBFs). This technique is based on taking advantage of the smooth amplitude and phase behaviors of the fields generated by a CBF when the distance is sufficiently large. Computational efficiency is realized by calculating the reaction between a source-CBF and a test-CBF by first evaluating a sampling of the field at a sparse set of points, and then computing the fields at the rest via the use of interpolation. Thus, this procedure avoids the highly expensive integration in the source domain that is needed to calculate the radiated field in the entire test domain when following the conventional procedure. Phase unwrap prior to interpolation and the fast sample calculation scheme are detailed in the article. The technique has been validated by considering several examples involving Radar Cross Section computations. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1818-1824, 2009 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24478