Low loss SAW double-mode structure suppressing spurious radiation

Takashi Shiba, Shinichiro Oosawa, Junichi Hamasaki, Vuji Fujita, Takao Chiba

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)


The transverse-double mode interdigital transducer (IDTs) structure on 42 deg. Y-X LiTaO3 was selected for low loss EGSM filter testing. We first observed a Leaky-SAW radiation pattern. SAW radiation patterns were obtained using a heterodyne interferometer-type laser probe method. Two spurious radiation modes were observed in the conventional double-mode structure. First mode wave traveled in almost the same direction as the main SAW response on the bus-bar edge. The direction of the second mode wave was rotated 40 deg. with respect to the main SAW direction. We succeeded in suppressing the first spurious mode by using a grating bus-bar structure which reduces the SAW velocity on the bus-bar edge. The first spurious wave was not observed and low loss frequency characteristics were measured in the new IDT structure. The grating bus-bar aperture was optimized by testing the shape factor and the insertion loss. The new structures improved the performance of the filter.

Original languageEnglish
Title of host publicationProceedings - 2004 IEEE Ultrasonics Symposium
Subtitle of host publicationA Conference of the IEEE International Ultrasonics, Ferroelectrics, and Frequency Control Society, UFFC-S
EditorsM.P. Yuhas
Number of pages4
Publication statusPublished - 2004 Dec 1
Externally publishedYes
Event2004 IEEE Ultrasonics Symposium - Montreal, Que., Canada
Duration: 2004 Aug 232004 Aug 27

Publication series

NameProceedings - IEEE Ultrasonics Symposium
ISSN (Print)1051-0117


Other2004 IEEE Ultrasonics Symposium
CityMontreal, Que.

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


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