Transducer Arrays Suitable for Acoustic Imaging
Abstract
The design and development of piezoelectric transducer arrays suitable for use in electronically scanned and focused acoustic imaging systems is described. These arrays are designed to operate in the frequency range 2-5 MHz within 45% to 80% fractional bandwidths. Linear arrays of up to 180 elements have been built and used extensively in acoustic imaging systems. Particular attention is placed on achieving high transduction efficiency and angular beam- widths of at least + or - 15 deg. Design techniques based on the transmission line model of the transducer of Krimholtz, Leedom, and Matthaei are formulated for achieving efficient, broadband operation. These techniques involve the use of quarter-wave matching layers between a high impedance ceramic and a low impedance load. Broadband matching criteria are generated, and a novel technique for selecting the quarter-wave matching layer impedances is described. The theoretical transient response of the transducer is obtained by taking the Fourier transform of the transfer function of the transducer. An experimental transducer built using the formulated design techniques is described and its characteristics compared to theory. Slotted transducer arrays employing tall, narrow elements are described. A one-dimensional model of this kind of element is formulated, and the effects of coupling between element resonant modes are examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1978
- Accession Number
- ADA080970
Entities
People
- Charles S. Desilets
Organizations
- Stanford University