SAR evaluation for multiple wireless communication devices inside a vehicle

In this paper, the specific absorption rates (SAR) evaluation in the scenarios of passengers using different wireless communication devices inside a vehicle is evaluated. The effects of the devices with different operational frequencies 900MHz/1.8GHz/2.4GHz, and different seating locations on the SARs are investigated. A computer simulation for SAR distributions in a human body was performed based on the FDTD method. Results have indicated that the SAR variation human body could be 30% when using two wireless communications devices inside a vehicle. As the 900MHz mobile devices generate a high output radiation power, it could induce about one-tenth of its maximum SAR value to the other mobile device users in the vehicle. This SAR value is sufficient to increase the SAR induced in the 2.4GHz mobile device user by twofold. However, the SAR value is still lower than the SAR induced in the 900MHz mobile devices user.