手臂电磁通道特征研究

Investigation of electromagnetic channel characteristics for human arm

依据现有研究结果和未来体域网发展趋势研究了手臂电磁通道特征.将两个同样工作在5.8 GHz、尺寸为4 cm×4 cm的全织物贴片天线作为收发两端,研究竖直状态下手臂的传输特征;再依据自然行走状态,模拟前摆最大值位置、自然下垂和后摆最大值位置手臂的动态过程.通过对天线在空气和手臂不同位置上传输特征的对比分析,确定表面波对传输特征的影响,并采用曲线拟合方法获得相对路径损耗预测模型;通过对比手臂三种自然状态的实测结果,建立路径损耗的预测模型.研究表明,对自然下垂状态下的预测模型进行简单的修正即可较好地预测前摆和后摆时的路径损耗.

Depending on the present researches and the trend of future body area network(BAN),this paper investigates the electromagnetic channel characteristics for human arm.Two same all-fabric patch antennas,working at5.8 GHz and with the size of 4 cm×4 cm,are taken as the transmitted and received antennas to study the transmission characteristics in the upright situation.And three classic positions are chosen to mimic the activity of arm in the process of natural walk,they are the maximum position of front swing,natural sagging,and maximum for the back swing.From the comparisons of different positions between the measured results in the air and those of on arm,the influence of surface wave is determined,and its predictive model is derived for the relative path loss by means of mathematical fitting method.The corresponding path loss models are also built for the above natural positions.The results show that the simple minor corrections for the path loss model of natural sagging can be used to predict the channel characteristics for the other two situations.