Abstract: Super-low frequency electromagnetic wave (30-300 Hz) has a small path loss in water and soil, so it plays an irreplaceable role in submarine, mine emergency, earthquake prediction and military fields. The radiation characteristics of moving magnetic dipoles were studied to realize the miniaturized and low-power comsumption ultralow frequency mechanical antenna. To explore the radiation characteristics of a moving magnetic dipole, an alternating magnetic field and super-low frequency electromagnetic waves are generated by controlling the rotation of permanent magnet. The rotating permanent magnet is equivalent to its surface ampere current. According to Faraday's law of electromagnetic induction, the parameters of the permanent magnet and the measured distance are introduced to establish a radiation power analytical model based on the ampere current model. The relationship between the influencing factors and the radiated power of rotating permanent magnet is studied, and the binary digital frequency (2FSK) signal modulation is used for communication experiments. The experimental results show that the radiation power of rotating permanent magnet in space is proportional to the square of magnetic remanence of permanent magnet and the third power of its volume, and is inversely proportional to the fourth power of test distance; the super-low frequency communication is realized by real-time control of speed and time-frequency domain transformation of signal.

Key words: antenna, super-lowfrequencyelectromagneticwave, magneticdipole, rotatingpermanentmagnet, amperecurrent, radiantpower