Homogenization of Voxel Models using Material Mixing Formulas

In this paper, we develop a procedure for simplifying highly inhomogeneous numerical phantoms based on dielectric mixing formulas. Numerical phantoms are extremely important in designing microwave imaging systems and algorithms. However, most of the realistic phantoms, typically obtained from magnetic resonance imaging (MRI) or computerized tomography (CT) scans are unsuitable for realtime analysis due to unlikely requirements for computational power and long processing time. Hence, it is of great importance to simplify such models without sacrificing the accuracy of the electromagnetic analysis. Here, we obtain simplified models by replacing a group of voxels by an effective permittivity computed by means of Looyenga and Lichtenecker methods. To assess the accuracy of the homogenized models with different resolutions, we compare their radar cross sections as well as transmissions between the antennas placed in their vicinity.