A Report on Human Head Exposure to a 2.6 GHz Mid-Band of 5G by Using FDTD Method

This paper presents a simulation result of human head exposure to 2.6 GHz, which is one of the bands used in the recently launched 5G mobile networks. The method adopted in the simulation is Finite-Difference Time-Domain (FDTD), which divides the computational domains into a physical and an artificial absorbing domains. The physical domain consists of a dipole antenna representing the mobile phone and a human head model created by a set of 53 layers from Magnetic Resonance Imaging (MRI). The artificial absorbing domain is a 3-D reflectionless boundary which can be implemented by using Perfectly Matched Layers (PML). Also, the Specific Absorption Rate (SAR) value is averaged over 1 gram of the head tissues when the dipole is placed in the range of 1-10 cm from the human head. Additionally, the total power absorption computed from the electric field is also reported. The results suggest that as the distance between the mobile phone set and the human head increases, SAR decreases monotonically and exponentially. Meanwhile, with operating frequency 2.6 GHz, the power absorption tends to decrease but possibly increases at some particular distance. The key result is that for a radiated power of 0.6 W, none of the distances under test deliver SAR value that meet the 1.6 W/kg of the FCC standard. The simulation results conclude that the radiated power of approximately 0.25 W assures the compliance with the FCC standard at the distance of 1 cm.