Study on the bulk wave radiation of finite-length SAW devices using FEM/BEM  

作　　者：WANGWeibiao ZHANGXiaodong SHUIYongan ZHANGDe HANTao 

机构地区：[1]StateKeyLaboratoryofModemAcoustics,InstituteofAcoustics,NanjingUniversity,Nanjing210093,China [2]ShanghaiJiaotongUniversity,Shanghai200030,China

出　　处：《Progress in Natural Science:Materials International》2005年第5期402-406,共5页自然科学进展·国际材料（英文版）

基　　金：Supported by National Natural Science Foundation of China (Grant Nos.10074034 and 10304012), and by the State Key Laboratory on Modern Acoustics of Nanjing University

摘　　要：Based on the distributions of stress and free charge on the interface of thesurface acoustic wave (SAW) device calculated with the combination of boundary element method andfinite element method(FEM/BEM), the power of each of the three possible bulkwaves radiated by theSAW device is calculated, and their contributions to the overall input conductance are separatedrespectively. Moreover, the formula of angular distributions of their power radiation into thesubstrate is derived. Consider the effect of mass loading, the resistance density, defined as ascalar, is extended to generalized resistance densities which can be written as three 4 X 4 tensorsand for which the formulas are derived. The bulk wave radiations for a synchronous one-portresonator on 42° Y-rotated LiTaOs are simulated. It is found that the radiated energy by slow shearwave contributes a very high proportion to input electrical energy in some frequency range.Based on the distributions of stress and free charge on the interface of the surface acoustic wave (SAW) device calculated with the combination of boundary element method and finite element method(FEM/BEM), the power of each of the three possible bulk waves radiated by the SAW device is calculated, and their contributions to the overall input conductance are separated respectively. Moreover, the formula of angular distributions of their power radiation into the substrate is derived. Consider the effect of mass loading, the resistance density,defined as a scalar, is extended to generalized resistance densities which can be written as three 4×4 tensors and for which the formulas are derived. The bulk wave radiations for a synchronous one-port resonator on 42°Y-rotated LiTaO 3 are simulated. It is found that the radiated energy by slow shear wave contributes a very high proportion to input electrical energy in some frequency range.

关 键 词：SAW device bulk wave radiation FEM/BEM 

分 类 号：O42[理学—声学]