Tapered transmission line technique based graded matching layers for thickness mode piezoelectric transducers

Author

Ramadas, S.N. ; Leary, R. L O ; Mulholland, A.J. ; Hayward, G. ; MacKintosh, A.R. ; Troge, A. ; Pethrick, R.A.

Author_Institution

Centre for Ultrasonic Eng., Univ. of Strathclyde, Glasgow, UK

fYear

2009

fDate

20-23 Sept. 2009

Firstpage

1695

Lastpage

1698

Abstract

Conventionally, in order to acoustically match thickness mode piezoelectric transducers to a low acoustic impedance load medium, multiple quarter wavelength (QW) matching layers are employed at the front face of the device. Typically a number of layers, 2-4 in number, are employed resulting in discrete impedance steps within the acoustic matching scheme. This can result in impedance matching with limited bandwidth characteristics. This paper investigates the application of tapered transmission line filter theory to implement a graded impedance profile, through the thickness of the matching layer scheme, to solve the impedance mismatch problem whilst accounting for enhanced transducer sensitivity and bandwidth.

Keywords

acoustic impedance; matched filters; piezoelectric transducers; transmission line theory; acoustic matching scheme; graded matching layers; impedance mismatch problem; line filter theory; low acoustic impedance load medium; tapered transmission line technique; thickness mode piezoelectric transducers; transducer sensitivity; Acoustic devices; Acoustic transducers; Acoustic waves; Bandwidth; Filtering theory; Impedance matching; Matched filters; Piezoelectric transducers; Transmission line theory; Transmission lines; Acoustic transducers; graded matching layer; impedance matching; photopolymerisation; transmission line;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium (IUS), 2009 IEEE International

Conference_Location

Rome

ISSN

1948-5719

Print_ISBN

978-1-4244-4389-5

Electronic_ISBN

1948-5719

Type

conf

DOI

10.1109/ULTSYM.2009.5441463

Filename

5441463