Safety Assessment of Electromagnetic Environmental Exposure for GPS Antenna of Electric Vehicle

Abstract

The present GPS (global positioning system) is widely used in electric vehicle navigation; it is usually installed in the middle-to-rear position on the car’s roof, near the rear windshield. Since the GPS antenna operating frequency is 1.575 GHz, the health risk of the passengers in the car in this high-frequency electromagnetic exposure is a matter of concern. In this paper, we construct models for a GPS antenna, an electric vehicle, and a human body. Through the multiphysics field coupling calculation in COMSOL Multiphysics, a finite element simulation software, in both frequency domain and transient analysis, we obtain the electric field strength distribution, specific absorption rate, and temperature distribution of the human body at three positions inside the electric vehicle after being exposed to the GPS antenna radiation for 30 minutes. The peak human-induced electric field is 18.4 V/m, and the peak specific absorption rate is 0.193 W/kg. The 30 minute average maximum human-induced electric field is 1.6906 V/m, which is 3.1% of the ICNIRP limit, the 30 minute average whole-body SAR is 0.0036 W/kg, which is 4.5% of the ICNIRP limit, and the 30 minute average human core temperature rise is 0.06°C, which is 6% of the ICNIRP limit. In addition, we simulate the impact of three different vehicle shell materials on the level of electromagnetic exposure to the human body, which can provide reference for electromagnetic shielding design in automobiles. The results indicate that the induced electric field strength, specific absorption rate (SAR), and temperature rise in various parts of the human body did not exceed the standard limits in the latest version of ICNIRP. This suggests that the electromagnetic exposure from the GPS antenna in a typical automotive environment does not pose a threat to human health.