As generally known, the magnitude of the electric field of the plane wave does not change when propagating in free space but evanesces in the lossy material, thus the plane wave propagating in the tissue is studied to obtain the absorption path loss. As shown in the figure 1, the investigated geometry is a dielectric cube of 7mm x 7mm x 7mm, which has the properties of the fat. Through it, the plane wave propagates. The real and imaginary part of the permittivity in the model
is set as 2.214 and 0.573, respectively, obtained by the calculation from the corresponding optical parameter [12, 13].Several probes have been considered equally spaced in order to monitor the variation of the E-field with the distance from the source. PML (Perfect Matched Layer) has been considered as boundary condition in the direction of the propagation and the periodic ones in the