ANALYSIS OF ELECTROMAGNETIC SCATTERING USING ARRAYS OF FICTITIOUS SOURCES

The use of models of fictitious elemental current sources, located ins ide the scatterer to simulate the scattered field, has proved to be an efficient computational technique For analyzing scattering by metalli c bodies, This paper presents a novel modification of the technique in which the omnidirectional elemental sources are arranged in groups of array sources with directional radiation patterns, and the boundary t esting points are arranged in groups of testing arrays with directiona l receiving patterns, This modification which is motivated by physical understanding is equivalent to mathematical basis transformations. It renders the system matrix more localized and thereby enables the anal ysis of Larger bodies, The new approach is applied to the case of TM s cattering by a perfectly conducting square cylinder with side-length o f 20 lambda. Reduction of 50% in the number of the nonzero elements of the system matrix is achieved with virtually no degradation in the ac curacy of the radar cross section (RCS) calculations.