A magnetic field model of rectangular permanent magnets in a magnetic pendulum array

The magnetic pendulum array (MPA) is a novel mechanical antenna for efficient and portable ultra-low-frequency transmission. Its natural frequency is affected by the magnetic field of its rectangular permanent magnets. In this work, the influence of the magnetization of a permanent magnet on the demagnetizing field and the magnetic field of other permanent magnets is analyzed to accurately calculate the natural frequency, and a magnetic field model of the rectangular permanent magnets in an MPA is established to improve the calculation accuracy. The consistency of the theoretical model results is verified through experiments and simulations. Finally, the effect of sizes and distances of the permanent magnets on the natural frequency of an MPA is analyzed, providing theoretical guidance for the dynamic analysis of “A Mechanically Based Antenna (AMEBA).” This research has significance and practical application value in the optimization of the magnetic field characteristics and natural frequency calculation methods for AMEBA.