Compact metasurface track-side PIS antenna-based occupational electromagnetic exposure research of inspectors in the metro tunnel.

INTRODUCTION

With the advancement of Smart Urban Rail construction, the electromagnetic environment has become increasingly complex inside metro tunnels. Track-side inspectors may experience occupational radio-frequency (RF) exposure when conducting professional inspections in such a closed electromagnetic environment.

METHODS

In order to analyze the occupational electromagnetic exposure dose absorbed by the track-side inspectors,and explore a method to reduce the influence of RF electromagnetic radiation. We propose a compact metasurface track-side passenger information system (PIS) antenna at first, and verify its good radiation performance. Then we compare the electromagnetic exposure metrics in the track-side inspectors human model when they are exposed to the conventional track-side PIS antenna and the proposed track-side PIS antenna at 5.8 GHz.

RESULTS

The simulation results show that, the peak local specific absorption rate (SAR) is reduced by at least 39.83% in the trunk, skull, brain, heart, liver, and testes after the antenna is miniaturized by 53%.

DISCUSSION: The findings indicate that the proposed track-side PIS antenna can reduce the external radiation energy, thereby reducing its impact on the surrounding environment. This research provides a theoretical analysis for occupational RF exposure safety of track-side inspectors and offers a dosimetry reference for antenna design in metro tunnel communication systems.