Title :
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
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;
Conference_Titel :
Ultrasonics Symposium (IUS), 2009 IEEE International
Conference_Location :
Rome
Print_ISBN :
978-1-4244-4389-5
Electronic_ISBN :
1948-5719
DOI :
10.1109/ULTSYM.2009.5441463
