Research On Construction And Performance Of Mechanical Antenna System For Low Frequency Communication

Traditional longwave antennas generate electromagnetic radiation through electrical resonance in metal structures,so they typically require dimensions of hundreds or even kilometers to meet the requirements of operating frequency,which is not conducive to installation and maintenance.Mechanical antennas,on the other hand,use mechanical vibration to drive the internal electric or magnetic dipoles of materials to flip over to achieve electromagnetic radiation,which can break through the limitations of structural size and radiation efficiency to achieve miniaturized design of longwave antennas.At present,research on mechanical antennas mainly focuses on optimizing the electromagnetic performance of individual antennas,such as antenna radiation efficiency and transmission distance.However,research on signal transmission systems for mechanical antennas has not yet been conducted in depth.This article constructs a mechanical antenna communication system based on relaxor ferroelectric ceramic materials,and explores the performance of the developed mechanical antenna in practical communication systems for in-depth optimization.The research in this article includes the following aspects:Firstly,the working principles of permanent magnet type,electret type,and strain driven mechanical antennas were elaborated.Based on the equivalent circuit model of mechanical vibration,the influence of material parameters on the radiation efficiency of piezoelectric mechanical antennas was studied.The development of mechanical antennas using piezoelectric materials with high relative dielectric constant and high voltage dielectric constant is beneficial for improving the radiation performance of mechanical antennas.Secondly,a piezoelectric mechanical antenna based on relaxor ferroelectric ceramic materials is proposed,and the radiation performance of the piezoelectric mechanical antenna is studied using finite element simulation software.In order to improve the radiation performance of piezoelectric mechanical antenna systems,a piezoelectric mechanical antenna testing system based on relaxor ferroelectric ceramic materials was constructed,and the low-frequency signal transmission and broadband radiation performance of the system were studied.On the basis of this testing system,the mechanical antenna feeding unit was designed and optimized to obtain a mechanical antenna communication system with better radiation performance.Finally,in order to optimize the performance of the receiving unit of the mechanical antenna system,the signal receiving antenna was optimized and designed based on the mechanical antenna testing system.Design a signal modulation scheme for a mechanical antenna communication system based on a phase-locked amplifier,and test the far-field radiation performance and directionality of the system.The results show that the mechanical antenna communication system operates at a frequency of 700 kHz and achieves effective communication at a distance of 100 meters with an input power of less than 50 W.The signal strength reaches up to 2 pT.Experimental testing has verified that the radiation mode of the mechanical antenna is the same as that of the dipole antenna.Multi element array is an effective method to improve the radiation efficiency of the mechanical antenna.