In this paper, the problem of electromagnetic scattering from a 3D system of spheres is considered and
an iterative solution that accounts for multiple scattering is proposed. The Mie formalism used for a
single sphere is extended to account for multiple scattered fields between several particles. The
translational addition theorems for spherical wave functions are used to express the electromagnetic field
scattered by a sphere Si in terms of an incident field for a sphere Sk in a spherical coordinates system
attached to the sphere Sk. In this work, the numerical convergence of the method is discussed and
associated computational times are given. Numerical computations including Radar Cross Section
(RCS) and radiation patterns for various 3D configurations are presented. Some of them are compared
with free-space measurements made in the 8 to 100 GHz frequency band using vectorial network
analyzers.