Source equalization for SPUDT transducers

Author

Dufilié, Pierre ; Ventura, Pascal

Author_Institution

Thomson Components & Tubes Corp., Vernon, CT, USA

Volume

1

fYear

1995

fDate

7-10 Nov 1995

Firstpage

13

Abstract

The electroacoustic source strength for a periodic SAW transducer can be determined analytically. With the exception of sources close to the ends of the transducer, the source strength function does not depend on its position in the transducer. A Distributed Acoustic Reflection Transducer (DART) is not periodic and consists of two or more linewidths and strip periods. The source strength and effective source position of a strip is dependent on the widths and positions of the adjacent strips. Strips of a given width can exhibit source strength differences of 10% or more depending on their position in the DART. This paper presents two methods for predicting the source strength and effective position of a source in a DART. The first method uses an electrostatic Green´s function analysis. The second more complete method uses a mixed FEM/BEM analysis to obtain a more accurate result. Results of these two methods are compared for various transducer configurations. Using the above results a 112 MHz filter was designed and built on a 112°YX LiTaO ₃ substrate

Keywords

Green´s function methods; VHF filters; acoustic wave reflection; boundary-elements methods; finite element analysis; surface acoustic wave filters; surface acoustic wave transducers; ultrasonic transducers; 112 MHz; DART; DART filter design; LiTaO₃; LiTaO₃ substrate; SPUDT transducers; distributed acoustic reflection transducer; effective source position; electroacoustic source strength; electrostatic Green´s function analysis; mixed FEM/BEM analysis; periodic SAW transducer; source equalization; source strength function; strip periods; transducer configurations; Acoustic measurements; Acoustic reflection; Acoustic transducers; Computer simulation; Electrostatic analysis; Filters; Geometry; Green´s function methods; Strips; Surface acoustic waves;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE

Conference_Location

Seattle, WA

ISSN

1051-0117

Print_ISBN

0-7803-2940-6

Type

conf

DOI

10.1109/ULTSYM.1995.495532

Filename

495532