Study on Structural Design of Transmitter Electrodes and Surrounding Electric Field for Human Body Communication Based on Impedance Matching
Study on Structural Design of Transmitter Electrodes and Surrounding Electric Field for Human Body Communication Based on Impedance Matching
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基于阻抗匹配的人体通信发射电极及周围电场结构设计研究
DOI：
10.5136/lifesupport.24.70
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
K. Sasaki
中科院分区：
文献类型：
--
作者：
D. Muramatsu;Takahiko Yamamoto;K. Koshiji;F. Koshiji;K. Sasaki
人体通信是在可穿戴设备之间沿沿着进行的，该技术可潜在地用于体域网。在这项研究中，用于人体通信的发射器电极在10 MHz的FDTD方法进行了分析。该分析表明，电极的输入阻抗取决于电极的结构和尺寸。我们推导出近似公式来表达这些输入阻抗和设计参数之间的关系。例如，手表大小（24 × 24 mm）设备的电极设计为具有50 kHz的匹配输入阻抗，而不使用阻抗变换器或短截线。阻抗匹配条件下人体手臂电极周围的电场比不匹配条件下的电场强10~20 dB，且使用匹配电极时VSWR特性小于2。当接收到的信号具有足够的实际接收强度时，体表和体内以及设备上的电场和电流小于安全标准。天线的发射功率小于蓝牙的发射功率
Human body communication is carried out along the body surface between the wearable equipment, and this technology can be potentially used for Body Area Networks. In this study, transmitter electrodes for human body communication were analyzed at 10 MHz by FDTD method. This analysis has shown that the input impedance of the electrodes was dependent on the structure and dimensions of the electrodes. We derived approximation formulas to express these relationships between the input impedance and the design parameters. As an example, the electrodes for the wristwatch-sized (24 × 24 mm) device were designed to have a matched input impedance of 50 without using impedance transformers or stubs. The electric field around the electrodes on the human arm under the impedance-matched condition was 10~20 dB stronger than that of the mismatched condition, and the VSWR characteristics were less than 2 when the matched electrodes were used. The electric fields and currents on the body surface and inside the body, and those of the equipment, were less than the safety standards, when the received signal had sufficient strength for practical receivers. The transmission power of the antenna was less than that of Bluetooth