Computed SAR and field exposure threat assessment for vehicle occupants

Numerical simulations of SAR induced in vehicle occupants due to on-board radio transmissions have been used to investigate possible approaches for assessing compliance with electromagnetic field exposure recommendations. The simulations employed 3D numerical models based on real vehicle geometry and human simulants of realistic size and shape. Results have been obtained for transmissions from a number of simple on-board antenna installations at frequencies of 400 MHz, 900 MHz, 1.8 GHz and 2.4 GHz. Comparing the average empty vehicle field with field reference levels provides a reasonable safety factor for the basic restrictions at 400 MHz and 900 MHz. However, comparison of results obtained from identical source positions at 900 MHz, 1.8 GHz and 2.4 GHz suggest that a more cautious approach may be required for frequencies above 1 GHz.