%0 Journal Article
%T Efficient evaluation of antenna fields by a time-domain multipole analysis
%A J. Adam
%A L. Klinkenbusch
%J Advances in Radio Science : Kleinheubacher Berichte
%D 2009
%I Copernicus Publications
%X The contribution describes a systematic method to efficiently determine frequency-domain electromagnetic antenna fields and characteristics for a broad spectrum via a single time-domain (e.g., Finite-Difference Time-Domain, FDTD) calculation. From a time-domain simulation of an antenna driven by a wide-band signal, a single modified Fourier transformation yields the frequency-domain multipole amplitudes. The corresponding multipole expansions are valid for the entire spectrum of the input pulse and at any point outside a minimum sphere enclosing the antenna. This allows a computationally cheap and elegant post-processing of arbitrary antenna characteristics. As an example of use the method is applied to determine high-resolution three-dimensional radiation patterns of an antipodal Vivaldi antenna.
%U http://www.adv-radio-sci.net/7/43/2009/ars-7-43-2009.pdf