Fine Positioning Three-Dimensional Electric-Field Measurements in Automotive Environments
Fine Positioning Three-Dimensional Electric-Field Measurements in Automotive Environments
复制标题
汽车环境中的精细定位三维电场测量
DOI：
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发表时间：
2007
影响因子：
6.8
通讯作者：
T. Nojima
中科院分区：
文献类型：
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作者：
Y. Tarusawa;S. Nishiki;T. Nojima
介绍了一种精密定位系统，它可以测量装有蜂窝无线电天线的客车周围的三维电场空间分布。该测量系统由非金属材料构建，以减少机械手引起的电场波动，使用气动马达机构，产生优于10 mm的场传感器空间分辨率。测量电场强度的不确定度估计为+4分贝，即变化在4分贝以内。针对三种天线：行李箱盖天线、后窗天线和车顶天线，给出了轿车车内和车外详细的电场分布。测量结果表明，当天线输入净功率小于1W时，前后座电场强度均小于30V/m。在车内，后备箱盖和车顶天线的局部场强峰值分别高出2d B和4d B，后窗天线的局部场强峰值约高10d B。车内和车外的电场都不超过4级(30V/m)规范，这是IEC电磁兼容标准中定义的电子设备的抗扰度级别之一。此外，测得的电场强度低于国际非电离辐射防护委员会推荐的人体暴露在射频电磁场中的参考水平。在对人体和电场之间的最大耦合进行保守估计时，最大场强为30V/m，作为900 MHz频率下的特殊平均值，相当于相对于一般公众规范的全身比吸收率基本限制0.08W/kg的一半。并对车外三种天线的远场分布差异进行了估算。
A fine positioning system is introduced that measures the 3-D electric-field space distributions around passenger cars that are equipped with cellular radio antennas. The measurement system, which is constructed of nonmetallic materials to reduce the electric-field fluctuation that is caused by the manipulator, uses an air-motor mechanism that yields a field sensor spatial resolution of better than 10 mm. The uncertainty of the measured electric-field strength is estimated as plusmn4 dB, i.e., variations are within 4 dB. Detailed electric-field distributions inside and outside the passenger car are derived for three antennas: a trunk-lid antenna, rear-window antenna, and roof antenna. The measurement results show that the electric-field strengths in the front and back seats are less than 30 V/m when the antenna input is less than 1 W as the net power. Inside the car, the local peak of the field strength is higher by 2 and 4 dB for the trunk lid and roof antenna, respectively, and approximately 10 dB higher for the rear-window antenna. The electric fields both inside and outside the car do not exceed the Level 4 (30 V/m) specification, which is one of the immunity levels for electronic devices defined in the IEC electromagnetic-compatibility standard. In addition, the measured electric-field strengths are lower than the reference levels for human exposure to RF electromagnetic fields, which are recommended by the International Commission on Non-Ionizing Radiation Protection. At maximum, the field strength of 30 V/m as a specially averaged value at the frequency of 900 MHz corresponds to half of the whole body specific-absorption-rate basic restriction of 0.08 W/kg with respect to specifications for the general public, when assuming conservative estimates for the maximum coupling between the human body and the field. The differences in the far-field distributions of the three antennas outside the car are also estimated