Grid Size Sensitivity of Field and SAR Calculations using the FDTD Method

An accuracy study of the electromagnetic calculations for the determination of fields inside the human head of the user of a mobile telephone has been performed. Because of the simplicity of the set-up and therefore allowing unambiguous interpretations, we used a dipole antenna as the radiator and a homogeneous lossy sphere as the absorber of the fields. An extensive study of the discretisation of the grid was undertaken with the aim to determine the grid size needed to obtain SAR results that are accurate enough to be compared with the proposed safety limits.