Title :
Characterization of high-frequency, single-element focused transducers with wire target and hydrophone
Author :
Bin Huang ; Shung, K. Kirk
Author_Institution :
Dept. of Biomed. Eng., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
In this paper, a wire-target technique was used for lateral beam profile measurements for a single-element, focused transducers in the very high-frequency range (35-60 MHz). Two wire targets made from 9-cm long tungsten wires with diameters of 8 /spl mu/m and 20 /spl mu/m were used as the pulse-echo targets to measure the lateral beam profiles at the focal plane of two single-element, focused transducers, a spherically focused 40 MHz transducer and a lens-focused in-house lithium niobate (LiNbO/sub 3/) 60 MHz transducer. For comparison, measurements on the same transducers were performed by three small-aperture hydrophones with geometrical diameters varying from 37 /spl mu/m to 150 /spl mu/m. Tomographic reconstruction of the acoustic field from the spherically focused transducer also was conducted. Results obtained with the wire-target technique are comparable to those obtained with small-aperture hydrophones in characterizing lateral radiation patterns of a single-element, focused transducer in the high-frequency range (35-60 MHz). However, the wire-target method may overestimate pulse length because of the additional attenuation caused by the return path. Compared to small-aperture hydrophones, the wire-target technique is simpler and more cost effective. Its major advantage, however, is in the frequency range above 100 MHz in which commercial hydrophones are not yet available.
Keywords :
hydrophones; lithium compounds; tungsten; 10 micron; 18.5 to 75 micron; 35 to 60 MHz; 4 micron; 40 MHz; 60 MHz; LiNbO/sub 3/; W; beam profile measurements; lateral radiation patterns; lens-focused in-house lithium niobate transducer; pulse-echo targets; small-aperture hydrophones; spherically focused transducer; tungsten wires; wire target technique; Acoustic beams; Acoustic measurements; Acoustic transducers; Lithium niobate; Performance evaluation; Pulse measurements; Sonar equipment; Tomography; Tungsten; Wire;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2005.1516034