ELECTROMAGNETIC SCATTERING BY AN AGGREGATE OF SPHERES - FAR-FIELD

In electromagnetic multisphere-scattering calculations the reexpansion method for seeking a single-field representation of the total scatter ed field is found impracticable because of severe numerical problems. We present a simple single-field expansion of the total scattered far field based on an asymptotic form of vector translational addition the orems. With this asymptotic expansion of the far field, we derive anal ytical expressions for the scattering properties of an arbitrary aggre gate of spheres. Resulting formulas are free from numerical problems i n practical applications. Theoretical predictions from this far-field solution for various aggregates of spheres that we tested agree favora bly with laboratory microwave scattering measurements. Some numerical results are presented and compared with experimental data. (C) 1997 Op tical Society of America.