Fast SAR assessment using spherical modes

This paper focuses on the Specific Absorption Rate (SAR) assessment using a rapid and non-invasive method. To achieve this goal, we propose to calculate the SAR starting from the radiated fields of a mobile phone and to identify their signature from a pre-determined data base of measurements. The method is demonstrated through a set of simulations performed using the Finite-Difference-Time-Domain (FDTD) method. The radiated fields of a mobile phone model are calculated and expressed into “spherical traces”. The method is based on the introduction of a Correlation Factor (CF) used for comparing the spherical traces. Even if the SAR is a scalar variable while the fields are complex vectors, we found a high correlation between the obtained SAR and the propagated fields outside the head. Moreover, for high Correlation Factors (of the order of 90%), it is found that the SAR obtained for the compared mobile phones are similar (differences less than 10%).