Modeling And Simulation Of Nonlinear Model Of BAW Device

With the development of 5G mobile communication technology,wireless communication expands to higher frequency band.The traditional RF filter can not meet the technical requirements of miniaturization,high frequency broadband,high power and high linearity of RF front end.BAW filter based on bulk acoustic wave(BAW)technology has the characteristics of small volume,low loss and integration.The RF filters and duplexers constructed by BAW resonators have the advantages of small package size,high quality factor Q value,easy integration with traditional RF links and so on,and become the best RF front-end frequency control solution.This paper focuses on the modeling and Simulation of BAW resonator used in 5g communication,and studies the nonlinear modeling and simulation method of BAW resonator for the technical difficulties of high linearization.The main work of this paper is as follows:(1)In this paper,the basic piezoelectric theory for the analysis of BAW resonators is summarized.Based on this theory,the vibration equation of BAW resonators is derived.The common structure and basic performance parameters of BAW resonator are introduced.(2)Based on the in-depth understanding of the theory of bulk acoustic wave,the Mason model,BVD model and mBVD model of BAW resonator are theoretically derived from the impedance expression of BAW.(3)The performance of BAW resonator is simulated by using ads and MATLAB software in the mBVD model.The influences of the piezoelectric layer's different elastic constants,dielectric constants and metal electrode's different area and density on the resonator's Q value and effective electromechanical coupling coefficient k_eff~2.(4)Combining with the basic theory of nonlinear system,starting from the H-type(fourth class)piezoelectric constitutive equation,the electrode and the piezoelectric layer are regarded as particle and spring respectively,and the nonlinear response mBVD equivalent circuit model of the BAW resonator is derived by using the first-order perturbation analysis.The calculation expressions of each discrete parameter and node voltage and current in mBVD equivalent model are given in detail.A series of linear simulations are designed to verify the accuracy of the model in linear working state.The results show that the model agrees well with the measured data of the ALN resonator in the linear working state.(5)MATLAB software is used to fit the nonlinear mbvd model with the second-order nonlinear output curve of AlN resonator,and the nonlinear undetermined coefficient of the nonlinear source in the model is calculated.The results show that the nonlinear mbvd model can well simulate the second-order nonlinear characteristics of BAW resonators,and can be used for nonlinear prediction of AlN piezoelectric resonators.