Simulation of solidly mounted BAW resonators using FEM combined with BEM and/or PML

Finite element method (FEM) has become an important approach in the modeling of bulk acoustic wave (BAW) resonators. Unfortunately FEM is not capable of describing unbounded regions, the substrate and the sides of the resonator. Perfectly matched layer (PML) can be used to prevent artificial reflection of the wave on the clamped sides, while the substrate is traditionally modeled by a boundary element method (BEM). This work presents numerical simulation of solidly mounted BAW resonators where both PML and BEM are used to model the substrate. With the correct adjustment of PML parameters, the resonator impedance computed with the FEM/PML model approaches the FEM/BEM results, both are in good agreement with the measured data.

[1]  Non periodic acoustic devices radiating in semi-infinite solids simulated by a combination of finite element analysis and a boundary element method , 2004, IEEE Ultrasonics Symposium, 2004.

[2]  R.C. Peach.  6D-3 Simplified Green Function Techniques for General SAW Device Analysis and Optimization , 2006, 2006 IEEE Ultrasonics Symposium.

[3]  B. Dubus,et al.  Solidly Mounted Resonator (SMR) FEM-BEM Simulation , 2006 .

[4]  Sabine Zaglmayr,et al.  8E-4 Perfectly Matched Layer Finite Element Simulation of Parasitic Acoustic Wave Radiation in Microacoustic Devices , 2007, 2007 IEEE Ultrasonics Symposium Proceedings.

[5]  Marc Solal,et al.  Numerical methods for SAW propagation characterization , 1998, 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).

[6]  R. Aigner,et al.  Optimization of acoustic dispersion for high performance thin film BAW resonators , 2005, IEEE Ultrasonics Symposium, 2005..

[7]  Reinhardlerch.  Simulation of Piezoelectric Devices by Two- and Three-Dimensional Finite Elements , 2000 .

[8]  Hans Petter Langtangen,et al.  Computational Partial Differential Equations - Numerical Methods and Diffpack Programming, Second Edition , 2003, Texts in computational science and engineering.

[9]  Vincent Laude,et al.  Energy storage and dispersion of surface acoustic waves trapped in a periodic array of mechanical resonators , 2009 .

[10]  3d piezoelectric surface green~s function , 2005, IEEE Ultrasonics Symposium, 2005..

[11]  Bulk Acoustic Wave Resonators 3D Simulation , 2007 .

[12]  Hans Petter Langtangen,et al.  Computational Partial Differential Equations - Numerical Methods and Diffpack Programming , 1999, Lecture Notes in Computational Science and Engineering.

[13]  R. Lerch,et al.  3F-1 Perfectly Matched Layer Technique for the Numerical Computation of Wave Propagation Phenomena , 2007, 2007 IEEE Ultrasonics Symposium Proceedings.