Scattering and Absorption Efficiencies for Nonspherical Dielectric Objects-Biological Models

The Extended Boundary Condition Method (EBCM) is used to calculate electromagnetic scattering and absorption efficiencies (cross sections normalized to the geometric shadow area) for nonspherical objects composed of dissipative dielectric material. The technique is applicable to homogeneous and isotropic objects with electrical size weli into the resonance region. The Forward Amplitude Theorem is used to determine the absorption efficiency from the scattered field. The capabilities of the method are demonstrated by making numerical calculations for a lossy prolate spheroid representing a 0.32 kg rat, a commonly used laboratory animal in microwave biological effects research. Numerical results show the dependence of the efficiencies on the electrical size of the model and the angle of incidence of the arriving wave. Polar plots of the differential cross section give the spatial distribution of the scattered radiation. The specific results generated here should be useful in the design of microwave biological effects experiments and in the interpretation of laboratory results.