Analysis of Rayleigh-Mode Spurious Response Using Finite Element Method/Spectrum Domain Analysis for Surface Acoustic Wave Resonator on Nonflat SiO2/Al/LiNbO3 Structure

作者：Nakamura Hiroyuki^*; Nakanishi Hidekazu; Goto Rei; Hashimoto Ken ya; Yamaguchi Masatsune

来源：Japanese Journal of Applied Physics, 2010, 49(7): 07HD20.

DOI：10.1143/JJAP.49.07HD20

Because of their low insertion loss, high out-of-band rejection, and high power durability, miniature surface acoustic wave (SAW) duplexers are widely used in mobile phones. Substrate materials substantially limit and determine the performance of SAW duplexers; for their applications to Band I and Band IV systems with large pass-band widths and wide frequency separations between the transmitting and receiving frequency bands, a larger coupling coefficient (K-2) is of primary importance. We have developed a shape-controlled SiO2 film/Al electrode/LiNbO3 substrate structure for their applications. It could lead to a large K-2 and suppression of Rayleigh-mode spurious response. In this paper, we report the analysis using finite element method/spectrum domain analysis (FEM/SDA) for the SAW resonator on a nonflat SiO2 film/Al electrode/LiNbO3 structure. It was clarified that the shape-controlled SiO2 was effective in terms of achieving a large K-2 for the SAW resonator with suppressed Rayleigh-mode spurious responses and bulk wave radiation. Furthermore, the experiment results showed a good agreement with the analysis results.

• 出版日期2010