典型地铁站台射频天线电磁暴露安全评估

为有效评估典型地铁站台射频天线对乘客电磁暴露的安全性,设计地铁站台无线通信系统吸顶天线和乘客人体模型,利用基于有限元的电磁仿真软件,构建吸顶天线辐射下的地铁站台乘客候车电磁环境模型,研究候车乘客的公众电磁暴露问题。结果表明:天线分别工作在900和2 440 MHz时,人体组织的平均比吸收率最大值分别为4.441×10-7和1.165×10^-6W·kg^-1,电场强度最大值分别为0.139和0.148V·m^-1,平均比吸收率在人体组织内的衰减均大于电场强度的衰减;2 440MHz时的射频电磁能量在颅内的穿透能力小于900MHz时;所有计算值均低于国际非电离辐射委员会制定的公众电磁暴露限值,说明地铁站台射频天线对乘客的电磁暴露不会构成健康威胁。

Safety Evaluation on Electromagnetic Exposure of Radio Frequency Antenna in Typical Subway Platform

In order to effectively evaluate the safety of passenger electromagnetic exposure to radio frequency(RF)antenna in typical subway platform,the ceiling antenna of the wireless communication system on the subway platform and the human body model of passenger were designed.The finite element based electromagnetic simulation software was employed to establish the electromagnetic environment model of waiting passengers on the subway platform under the radiation of ceiling antenna and study the public electromagnetic exposure for waiting passengers.Results show that,when the antenna works at the frequencies of 900 and 2 440 MHz,the maximum value of the average specific absorption rate of human tissue is4.441×10^-7 and 1.165×10^-6W·k^g-1 respectively,and the maximum value of the electric field strength is 0.139 and 0.148 V·m^-1 respectively.The attenuation of the average specific absorption rate in human tissue is greater than that of electric field strength.The penetrability of RF electromagnetic energy in the brain at 2 440 MHz is less than that at 900 MHz.All the simulation values are lower than the limit values for public electromagnetic exposure established by the International Commission on Non-Ionizing Radiation Protection(ICNIRP),which indicates that the electromagnetic exposure of RF antenna to passengers on subway platform will not pose a threat to human health.