Title :
A complex impedance model for SAW and LSAW propagation in periodic grating
Author :
Shui, Yongan ; Lu, Yming
Author_Institution :
Inst. of Acoust., Nanjing Univ., China
Abstract :
In this paper, we propose a Complex Impedance Model (CIM) for SAW and Leaky SAW (LSAW) propagating under periodic gratings. CIM starts with the postulation of impedance discontinuity, based on which a reflective grating is equivalent to a transmission line with complex impedance and complex propagation phase shift. As a result, the reflection and transmission of SAW and LSAW can be expressed in simple, analytical formulae. The model is compared with COM analysis and entire equivalence proved. Also a method is developed to extract CIM parameters such as center frequency, impedance mismatch coefficient, propagation attenuation coefficient and shunt susceptance element. As an example, numerical results for LSAW under gratings on 36-YX-LiTaO3 substrate are presented
Keywords :
acoustic impedance; acoustic wave diffraction; acoustic wave propagation; coupled mode analysis; diffraction gratings; surface acoustic wave devices; surface acoustic waves; 36-YX-LiTaO3 substrate; LSAW; LiTaO3; SAW; SAW devices; acoustic wave propagation behaviour; center frequency; complex impedance model; entire equivalence; impedance discontinuity; impedance mismatch coefficient; periodic grating; propagation attenuation coefficient; reflective grating; shunt susceptance element; Attenuation; Computer integrated manufacturing; Frequency; Gratings; Impedance; Reflection; Shunt (electrical); Surface acoustic waves; Transmission line discontinuities; Transmission lines;
Conference_Titel :
Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-2940-6
DOI :
10.1109/ULTSYM.1995.495580
