Abstract:
The transverse-mode spurious responses could be suppressed successfully by the selectively SiO2 removal at the dummy region. This paper discusses the suppression mechanis...Show MoreMetadata
Abstract:
The transverse-mode spurious responses could be suppressed successfully by the selectively SiO2 removal at the dummy region. This paper discusses the suppression mechanism of the transverse-mode spurious responses by the selectively SiO2 removal technique. The SAW field distribution was analyzed for the SiO2/Al/LiNbO3 structure. The field analysis indicated that the selectively SiO2 removalenhances the SAW reflection coefficient at the boundary between the interdigital and the dummy electrode regions. When the SiO2 thickness is large, full SiO2 removal from the dummy electrode region creates another transverse mode resonance. The laser probe observation revealed that it is due to the hybrid mode caused by the coupling of the SH SAW with the Rayleigh SAW at the lateral boundaries. It was also shown that the response can be suppressed by the partial SiO2 removal from the dummy electrode region. This might be explained by the weakened mutual coupling between the SH and Rayleigh SAWs at the lateral boundaries. This weakening is caused by the reduction of the SAW velocity difference between the dummy electrode and IDT regions.
Published in: 2011 IEEE International Ultrasonics Symposium
Date of Conference: 18-21 October 2011
Date Added to IEEE Xplore: 03 September 2012
ISBN Information: