摘要
根据HJ/T 10.2—1996中的微波远场轴向功率密度计算公式,对所选取典型WCDMA基站的安全防护距离进行了理论预测,并与实测得到的基站电磁辐射强度达标距离对比。结果表明,理论计算的安全防护距离在水平方向上较实测达标距离更为保守,在垂直方向上则较为接近。从发射功率、话务量、监测条件、建筑物干扰和WCD-MA基站特点等方面分析了实测结果与理论计算差异的产生原因,并基于基站副瓣和后瓣实测电磁辐射强度远低于理论预测值的实践,认为WCDMA网络基站运行时的电磁辐射强度超标范围应远小于理论计算结果,其所造成的电磁辐射对环境影响较小。
This paper would like to introduce the results of our comparative study of theoretical accounting and actual measuring results of the safety protection distance of WCDMA network base station. As a matter of fact, more and more mobile base stations have been set up with the advancement of urban mobile communication technology. And, in turn, problems are emerging on how to reduce the detrimental electromagnetic radiation of these stations to the surrounding buildings,offices,schools and hospitals. Wideband Code Division Multiple Access（WCDMA） technology of China Unicom is one representative of 3G networks, which are planning and constructing extensively. Based on the calculation formula for the microwave far-field axial power density from Guideline on the Management of Radioactive Environmental Protection Electromagnetic Radiation Monitoring Instruments and Methods, we have made necessary theoretical accounting and actual measuring of the safety protection distance of the network base stations. Here we found that the electromagnetic radiation of the base station can be measured by means of a Germany-EMR 300 electromagnetic analyzer. Compared with the actual values measured, the results of the theoretical prediction prove to be more conservative than that of actual measurements on the horizontal direction, but close to the vertical direction. The reasons for the discrepancy may account for a few reasons, such as transmission power, traffic, monitoring conditions, building interference and the features of WCDMA network station, etc. Due to the limited power control technology, the actual transmission power of the network station is likely to be weaker than the maximum values, but can also satisfy the system quality and the customers＆rsquo; demands. In addition, the discrepancy between the practical measurement and the theoretical calculation may also result from the diffraction, reflection of buildings, air absorption, blocking and the other factors. Combined to the practice of other lobes＆rsquo; electromagnetic radiation, it can be concluded that the range of the intensity of the electromagnetic radiation beyond the standard dements can be far less than that of theoretical prediction, and the environmental impact of such detrimental radiation turns to be rather minor. Therefore, it is essential for the builders of such base stations to ensure the safety distance and make the public deviate from the main lobe direction of the base stations while taking in full consideration the psychological effects of the general public.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第5期197-200,共4页
Journal of Safety and Environment
关键词
安全工程
WCDMA基站
安全防护距离
电磁辐射
环境影响
辐射防护
safety engineering
WCDMA base station
safety pro-tection distance
electromagnetic radiation
environ-mental impact
radiation protection
