Frequency domain analysis of lamb wave scattering and application to film bulk acoustic wave resonators

Abstract

This paper demonstrates a novel frequency domain analysis (FDA) to evaluate the scattering behavior of a waveguide mode at arbitrary scattering geometries by a time harmonic simulation based on the finite element method (FEM). To this end, we add an injection-damping mechanism (IDM) to avoid interference at the acoustic input port. The IDM can be easily constructed by a numerical operation. Our approach offers improved time consumption and calculation power necessary over the established method in the time domain. After checking the validity of the proposed method, we discuss the importance of considering wave scattering phenomena in film bulk acoustic wave resonator (FBAR) devices by applying the proposed method to two simplified models of an FBAR device.

From Microwave Acoustic Filters to Millimeter-Wave Operation and New Applications

“…In the figure, the horizontal axis is the frequency-AlN thickness product F , and F S1b , F S1c and F S2c are the frequencies at the cutoff for the S 1− , S 1+ , and S 2 Lamb modes, respectively. The same calculation was performed by conventional FEM [51]. Although the result was similar to this, it was impure due to strong mode conversion.…”

Design and simulation of coupled-resonator filters using periodically slotted electrodes on FBARs [Correspondence]

“…With appropriate design, wave reflection and mode conversion are not allowed even within the damping mechanism. The detailed design can be seen in [19].…”

A versatile heterodyne interferometer for vibration measurement and analysis of micro-structures

“…© 2020 The Japan Society of Applied Physics Supplementary material for this article is available online O ptical interferometry techniques have been widely studied due to direct, non-contact measurements of out-of-plane vibration fields which provide information for the design and performance of micro-structures. [1][2][3][4][5][6][7][8][9][10][11] Among these techniques, full field interferometers [12][13][14][15][16][17][18] are faster than scanning laser interferometers [19][20][21][22][23][24][25][26][27][28][29] in obtaining the whole vibration image. The frequency range and the amplitude range of these two types of interferometers are different.…”