Numerically Efficient Use of Frequency Domain MoM Codes for Wideband Radiation

摘要

A concise and numerically efficient method for the wide band or transientcharacterization of three-dimensional antennas or scatterers is presented. Assuming a situation where a frequency domain Method of Moments code already exists for the particular structure of interest, we extend the code to accept complex frequencies and use it to compute the natural resonances and modes. The desired wide-band spectrum is then expanded in terms of these modes, and the unknown expansion coefficients (the crux in any application of the Singularity Expansion Method) are determined by a least mean square match to a known reference case, also obtained with the existing code. The computational issues involved in using this approach are discussed. As an example, an analytic approximation for the radar cross section of a microstrip patch valid over the 1-18 Ghz range is derived, which uses only 15 natural modes. Wideband scattering, Microstrip patch radar cross section, Natural mode expansion, SEM.