Title :
New symmetric reflector ultrasonic transducers (SRUT)
Author_Institution :
Meas. Specialties Inc., Wayne, PA, USA
fDate :
10/1/2009 12:00:00 AM
Abstract :
This paper proposes a new structure composed of reflector plates mounted in front and in back of the transducer at an angle of 45deg, so that acoustic waves from front and back of the transducer are combined to form a single main beam. This principle is applicable to both transmitters and receivers. Because the propagation path lengths of the 2 beams are identical, they constructively add at all frequencies. Theoretical investigations revealed that far field directivity becomes sharper and acoustic pressure output is doubled. Experiments using an air ultrasonic transducer constructed of 50-kHz polyvinylidene fluoride corrugated film has shown doubled acoustic pressure in the far field, and the predicted sharper directivity has been observed. The reflector structure has been also applied to a 2.6-MHz lead zirconate titanate transducer in water with matching layers at both surfaces which has shown almost doubled bandwidth compared with an air backing structure, and doubled output power in continuous drive. Also pulse echo experiments have shown the effectiveness of this scheme.
Keywords :
lead compounds; plates (structures); polymer films; ultrasonic propagation; ultrasonic transducers; PZT; SRUT; acoustic waves; corrugated film; doubled acoustic pressure; far field directivity; frequency 2.6 MHz; frequency 50 kHz; lead zirconate titanate transducer; matching layers; polyvinylidene fluoride; propagation path length; pulse echo experiments; reflector plates; symmetric reflector ultrasonic transducers; ultrasonic receivers; ultrasonic transmitters; Acoustic beams; Acoustic propagation; Acoustic transducers; Acoustic waves; Corrugated surfaces; Frequency; Optical films; Titanium compounds; Transmitters; Ultrasonic transducers; Equipment Design; Lead; Models, Theoretical; Titanium; Transducers; Ultrasonography; Zirconium;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2009.1312