Research On Low Frequency Antenna Technology Based On Piezoelectric Materials

Low frequency electromagnetic wave has excellent penetration performance and has great application potential in underwater communication,submarine communication,geological exploration and other fields.The traditional low-frequency transmission system is often an electrically small antenna(ESA),which is large,difficult to maintain and has very low radiation efficiency.To solve this problem,this paper introduces mechanical antenna(MA)based on piezoelectric material,which is a new mechanism of low-frequency antenna system.MA applies voltage to the piezoelectric material to generate inverse piezoelectric effect,and generates electromagnetic wave radiation through the vibration of piezoelectric material.This paper is divided into three parts to introduce this antenna.1.According to the basic principle of piezoelectric material vibration,the overall design of low-frequency antenna based on piezoelectric material is completed.In this paper,cylindrical lithium niobate(LiNbO3)crystal is selected as piezoelectric radiation source and its vibration model is analyzed.Besides,PCB coupling structure is used to feed the crystal with single end coupling to ensure good electromagnetic wave radiation.2.multi physical field simulation software is used to simulate and analyze a single LiNb03 and the whole MA antenna,and the resonant frequency,stress distribution,vibration model and field strength distribution are obtained.The influence of PCB coupling ring on MA resonant frequency is also analyzed.3.The off-site test experiment of MA principle prototype is carried out.The test results show that the resonant frequency and input impedance of MA are close to the simulation results,and the radiation attenuation model is consistent with the dipole radiation,which proves the effectiveness of the antenna.In order to improve the radiation efficiency of the antenna,this paper designs the MA antenna array,and the experiments show that the radiation efficiency of the array antenna is greatly improved compared with a single MA antenna.