基于三相感应电机的小型化超低频发射天线研究

针对低频电磁传输中天线尺寸过大的问题,设计了一种基于三相感应电机的小型化超低频发射天线.电机工作时产生了时变低频电磁场,可作为超低频发射天线.为有效分析其电磁场分布,文章建立旋转磁偶极子数学模型以等效电机内部旋转时产生的磁场.首先,对电机内部磁场和旋转磁偶极子的关系进行阐述,利用麦克斯韦方程组,得到旋转磁偶极子的电磁场分布.其次,通过电磁仿真软件验证旋转磁偶极子的近场分布特性和远场辐射特性.最后,通过实验对电机近场的磁场分布进行验证.仿真和实测结果表明,三相感应电机具有超低频天线的辐射特性.

Miniaturized super low frequency transmitting antenna based on the three-phase induction motor

In this paper, a miniaturized super low frequency (SLF) transmitting antenna is proposed based on three-phase induction motor, in order to cope with the oversized antenna issue in low-frequency electromagnetic (EM) transmission.Equivalent time-varying low frequency electromagnetic fields can be generated by the working motor, which can be used as a transmitting antenna. For the sake of electromagnetic field analysis, rotating magnetic field inside the motor can be regarded as a model of rotating magnetic dipole. Firstly, this paper describes the relationship between the magnetic field of the motor and the rotating magnetic dipole, and the electromagnetic field distribution of the rotating magnetic dipole is obtained by Maxwell's equations. Secondly, its near field and far field characteristics are proved by electromagnetic simulation. Finally, the electromagnetic field distribution of the motor is verified through experiments. The results show that the three-phase induction motor has the radiation characteristics of the low frequency antenna.