Calculation of SAR in a Fetus Exposed to EMF from a Normal-Mode Helical Antenna with a Metallic Case close to the Abdomen of a Pregnant Woman

In this paper, the SAR distribution in the fetus was calculated using the numerical model of the pregnant woman by the NHA with the metallic case at 150 MHz. As a result, it has confirmed that the SAR of the NHA at 150 MHz in deep region of the maternal body (y ges 80 mm) is higher than that of the half-wave dipole antenna at 2 GHz. In addition, it has confirmed that the fetus averaged SAR is 38% higher than the whole body averaged SAR. Furthermore, it has confirmed the fetus and the fetal brain averaged SARs are approximately 0.1 W/kg when the radiated power of the antenna is 5 W. As a further study, the SAR in the fetus will be evaluated under various fetal positions and the temperature rise of the fetus will also be investigated to evaluate safety of the fetus when the pregnant woman is exposed to EM waves.