The null field approach to electromagnetic scattering from composite objects: the case with three or more constituents

A null-field approach to scattering from composite objects due to S. Strom and W. Zhengs (ibid., vol.36, no.3, p.376-82, 1988) is extended to scatterers consisting of three of more homogeneous parts. The numerical performance of this extension has been tested for a number of different types of scatterers, and the numerical results have been compared with other computed and measured results. In particular, the application of the extended formulation to scattering from elongated objects is described and illustrated by numerical computations