Optimisation of the homogenization of tissues using the adjoint method and the FDTD

This paper presents an application of the adjoint method associated to the finite-difference time-domain (FDTD) method for the homogenization of human bodypsilas models. This approach enables to obtain rather easily the sensitivity of a cost function of several variables. Hence, it can be used to synthesize a grid dependent homogenized structure equivalent to a multilayer structure. The proposed scheme results in weak errors on the received fields after reflections. Several homogenization schemes are studied. The equivalent grid homogenized model can then be used for faster analysis of induced electromagnetic fields.