一种可穿戴天线的研究

体模型图

加载模拟人体模型后，天线电压驻波比如图2绿色曲线所示，在2.24GHz-2.51GHz工作频率范围内，电压驻波比小于2，阻抗带宽达到270MHz，具有宽频带特性。天线谐振频点稍微向低频处偏移，这是由于加载人体后相当于加载复合介质，相当于使天线等效电长度增加了。天线增益方向图如图5所示，可以看到加载模拟人体后，天线方向图受到了影响，基本变成了单向辐射。这是由于模拟人体模型对天线辐射电磁波具有强反射，这同时也使得天线的主瓣增益提高。

四、总结

本文设计的工作于ISM 2.4GHz频段的正弦形可穿戴天线具有尺寸小，结构紧凑，容易加工等特点。天线通过巴伦馈电，带宽大于250MHz，电特性稳定。在CST仿真软件中对天线加载模拟人体进行建模仿真，在加载人体模型前后，天线谐振频率和阻抗带宽变化很小，辐射方向图稳定为单向辐射，最高增益可达5.88dBi。仿真结果可以看出，该天线的设计基本符合我们的需求，并且由于总体只有不到50mm，所以可以印刷在衣服的各个部位，具有良好的共形性，也不会影响到人体自身的活动性。

图5、加载模拟人体后天线立体增益方向图

作者：西安电子科技大学 徐乐凡 徐超龙

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