Dynamic Characteristics Of The Mechanical Antenna Based On Vibrating Permanent Magnet

In the traditional wireless communication field,long-wave communication requires largesized signal transmission antennas,restricting their use in medium and small-sized platforms.The mechanical antenna is a new type of low-frequency transmission antenna that utilizes the mechanical motion of electric charge or magnetic to generate the electromagnetic wave directly.This transmitting antenna have the potential to break physical size constraints of traditional antennas related to wavelength,achieving low-frequency communication in a smaller form factor.This opens broad application possibilities in complex communication environments such as underwater and underground.In this study,an electrical-mechanicalelectromagnetic energy theoretical model is established based on the inverse piezoelectric effect,vibration theory,and Maxwell’s equations.Firstly,a principle prototype of a threedegree-of-freedom reentrant beam structure for mechanical antenna is designed.Then,the influence factors of radiation are studied.Finally,a principle prototype of the mechanical antenna is fabricated,and the feasibility and effectiveness of the long-wave communication method are verified by theoretical analysis and experiments.Specific research includes:Firstly,guided by the theoretical analysis,a three-degree-of-freedom reentrant beam structure is designed,and a mechanical antenna principle prototype is developed.The first three natural frequencies and vibrational displacements of the permanent magnets are obtained by solving the dynamic differential equation of the structure,driven by the piezoelectric plate.Then,the radiation influence factors of the mechanical antenna are studied.According to the theoretical model,the expressions of the magnetic field intensity of the vibrating permanent magnets and the induced electromotive force of the receiving coil are derived.It is clear from the expressions that the magnetic field intensity and induced electromotive force are affected by the vibrational displacement,number and magnetism of the permanent magnet.The mechanical antenna communication transmission protocol is formulated based on the multimode characteristics of vibrational beam structure.To enhance communication effectiveness through more efficient and accurate decoding of the receiver signal,an optimization analysis of the excitation voltage is performed.Finally,the feasibility and effectiveness of the long-wave communication method are experimentally verified.A mechanical antenna prototype is designed and manufactured,with the consistency between the vibrational modes of the structure and the theoretical analysis results validated experimentally.Through experimental verification,it is found that the proposed long-wave communication principle prototype can facilitate short-distance communication both on land and underwater.This study combines the inverse piezoelectric effect,electromagnetism and vibration mechanics to achieve the excitation of low-frequency signals using a compact mechanical antenna.This provides a novel perspective for the design of mechanical antenna devices from both theoretical and technical.Importantly,this communication method can enable localized information exchange among swarm of bionic underwater vehicles.