Accurate computation of apodized SAW transducer capacitances
- 6 January 2003
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 23-28 vol.1
- https://doi.org/10.1109/ultsym.1988.49336
Abstract
The passband slope of a SAW (surface acoustic wave) filter with large fractional bandwidth critically depends on the value of the operating capacitances of the input and output interdigital transducer (IDT). To reduce the number of design cycles required to achieve a flat passband response, a program for the computation of all relevant contributions to the IDT capacitance was developed. For the analysis of the apodized transducer, a track division approach is used. The capacitance contributions from the different tracks are computed by means of an interfinger nodal capacitance matrix. As this matrix is calculated from the Green's function of the boundary value problem, the presence of the grounded back-plane and any nonconductive adhesive is automatically taken into account. The operating capacitances of two different SAW filters with center frequencies of 70 MHz and 140 MHz fabricated on YZ-LiNbO/sub 3/ were calculated and compared to measurements.Keywords
This publication has 7 references indexed in Scilit:
- High precision simulation of broadband SAW filtersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Rigorous 3D Electrostatic Field Analysis of SAW Transducers with Closed-Form FormulaePublished by Institute of Electrical and Electronics Engineers (IEEE) ,1986
- On the Calculation of Charge, Electrostatic Potential and Capacitance in Generalized Finite SAW StructuresPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1984
- Element Factor for Periodic TransducersIEEE Transactions on Sonics and Ultrasonics, 1980
- Analysis of Generation and Detection of Surface and Bulk Acoustic Waves by Interdigital TransducersIEEE Transactions on Sonics and Ultrasonics, 1977
- Acoustic surface waves in piezoelectric materials with periodic metal strips on the surfaceIEEE Transactions on Electron Devices, 1973
- Piezoelectric and Elastic Properties of Lithium Niobate Single CrystalsJapanese Journal of Applied Physics, 1967