https://scholars.lib.ntu.edu.tw/handle/123456789/352545
標題: | A Single-Element Transducer with Nonuniform Thickness for High-Frequency Broadband Applications | 作者: | J.-H. Liu S.-Y. Chen PAI-CHI LI |
公開日期: | 二月-2009 | 卷: | 56 | 期: | 2 | 起(迄)頁: | 379-386 | 來源出版物: | IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control | 摘要: | The design, fabrication, and evaluation of a highfrequency single-element transducer are described. The transducer has an annular geometry, with the thickness of the piezoelectric material increasing from the center to the outside. This single-element annular transducer (SEAT) can provide a broader frequency range than a conventional single-element transducer with a uniform thickness (single-element uniform transducer, or SEUT). We compared the characteristics of a SEAT and a SEUT. Both transducers used 36°-rotated, Y-cut lithium niobate (LiNbO3) material. The SEAT had a diameter of 6 mm and comprised 6 subelements of equal area (electrically connected by a single electrode on each side) whose thickness ranged from 60 °m (center) to 110 °m (outside), which resulted in the center frequency of the subelements varying from 59.8 MHz to 25 MHz. The overall center frequency was 42.4 MHz. The annular pattern was constructed using an ultrasonic sculpturing machine that reduced the root-mean-square value of the surface roughness to 454.47 nm. The bandwidth of the SEAT was 19% larger than that of the SEUT. However, compared with the SEUT, the 2-way insertion loss of the SEAT was increased by 3.1 dB. The acoustic beam pattern of the SEAT was also evaluated numerically by finite-element simulations and experimentally by an ultrasound beam analyzer. At the focus (10.5 mm from the transducer surface), the °6 dB beam width was 108 °m. There was reasonable agreement between the data from simulations and experiments. The SEAT can be used for imaging applications that require a wider transducer bandwidth, such as harmonic imaging, and can be manufactured using the same techniques used to produce transducers with multiple frequency bands. © 2006 IEEE. |
URI: | http://scholars.lib.ntu.edu.tw/handle/123456789/352545 https://www.scopus.com/inward/record.uri?eid=2-s2.0-62349084847&doi=10.1109%2fTUFFC.2009.1047&partnerID=40&md5=49a204a8ce508b11acdd991a6cd86573 |
ISSN: | 08853010 | DOI: | 10.1109/TUFFC.2009.1047 | SDG/關鍵字: | Acoustic waves; Frequency bands; Niobium compounds; Superconducting materials; Surface roughness; Telecommunication systems; Ultrasonic imaging; Ultrasonics; Acoustic beams; Annular geometries; Beam widths; Broadband applications; Center frequencies; Finite-element simulations; Frequency ranges; Harmonic imaging; High frequencies; Imaging applications; Lithium niobate; Multiple frequencies; Non-uniform thickness; Root-mean-square values; Single electrodes; Single-element transducers; Techniques used; Transducer surfaces; Ultrasound beams; Piezoelectric transducers |
顯示於: | 電機工程學系 |
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