Research Of Phononic Crystals In Surface Acoustic Wave Resonators

The swift advancement of mobile communication systems has necessitated greater performance demands for acoustic device technology.As the filter and sensor design unit,acoustic resonator design is also confronted with fresh needs.Surface wave resonators are radio frequency devices that combine acoustics,mechanics,and microelectronics.Widely employed in aerospace,mobile equipment,radar,intelligent monitoring,and electronic countermeasures,the advantages of high frequency,small size,high Q value,and low insertion loss make these systems highly sought-after in both military and civil sectors.Periodically arranged scatterers,known as phononic crystals,are a novel type of artificial composite materials.These crystals are extensively used in both military and civil industries,such as aerospace,mobile equipment,radar,intelligent monitoring,and electronic countermeasures,due to their high frequency,diminutive size,high Q value,and low insertion loss.Since their introduction,surface acoustic wave resonators based on phononic crystals have become a research area of great interest.This article first discusses the elastic band gaps of two-dimensional phononic crystals in depth,and focuses on how they improve the performance of Rayleigh wave resonators.The specific content includes:Firstly,based on theoretical analysis,the design of a two-dimensional phononic crystal cell model was studied.Firstly,a model was built based on COMSOL 5.4 software,and the basic design rules were analyzed and discussed using 3D-FEM simulation method.The effects of the scattering material,geometric size,lattice constant,and lattice type on the phonon band gap range and bandwidth in the "protruding" cylindrical twodimensional phononic crystals were emphatically discussed.Then,the different structures of two-dimensional phononic crystals,including "concave" cylindrical,"protruding" cross The energy band structure characteristics of the "concave" cross and the composite column are compared and the corresponding design rules are re studied.Subsequently,the simulation design of the basic parameters of the resonator is studied.To begin,a simplified model was employed to establish the fundamental design regulations,concentrating on the design regulations of Normal SAW structure resonators,including electrode materials,thickness,wavelength,and metallization rate,and their influence on electromechanical coupling coefficients.Submicron-sized Al PnCs were incorporated into the IDTs/120 ° YX-LiNbO3 structure Rayleigh wave resonator,the changes of resonator performance indicators before and after the introduction of phononic crystals were comprehensively studied,including the admittance alterations.Additionally,the electromechanical coupling coefficient and quality factor were once more examined.Finally,the geometric size,number,and delay distance from the interdigital electrode region of Al PnCs are discussed δ Improvements in resonator performance.Simulation data show that changing the above parameters can achieve the goal of optimizing different performance indicators,which provides a solution for designing resonators with different requirements.The above results indicate that phononic crystals can be used to design surface acoustic wave resonators with high Q values and miniaturization.