本論文探討一種新型的陣列式P(VDF-TrFE) 解析式超音波換能器，配合Angular Spectrum理論的聲場計算，針對不同材料進行量測與資料分析。傳統的超音波換能器缺乏聲場解析的能力，因為其工作原理是將一壓電材料所接收的所有聲場信號進行積分疊加，得到一個單一輸出電壓信號；如此一來，聲場的空間分佈資訊會遺漏，無法進行更詳盡的聲場解析與反算。是故，本文製作一陣列式P(VDF-TrFE) 解析式超音波換能器，在傳統聚焦式換能器鏡頭的內凹曲面上，以分割電極方式製作出陣列式感測單元，每個感測單元可以在特定的位置上接收信號並且獨立輸出其信號；此一設計可以完整接收來自散射體在不同位置與方向的聲波資訊，因此將具有較佳空間解析聲場的能力。此外，本論文使用Angular Spectrum理論來計算無缺陷的待測材料應得到之反射信號，再與實際量測無缺陷之待測物之反射信號做比較及分析，分析結果證實兩者信號趨勢是符合的，並且可以透過反射係數的差異，對於反射信號之變化去判定所量測為何種材料。

This thesis discusses the measurement results using a laboratory-made P(VDF-TrFE) analysis ultrasonic transducer and the analysis data predicted by angular spectrum theory. Traditional focusing ultrasound transducer gives only one voltage signal by integrating all received wave signals on the surface of a piezoelectric material. This integration process destroys some important information in the ultrasound field. In this thesis, a PZT/PVDF hybrid ultrasound focusing transducer is proposed, fabricated, and experimentally tested. This new type ultrasound transducer contains a number of independent PVDF hydrophone elements on the concave spherical surface of the transducer. Each PVDF element can recording the back-scattered wave signal reflected and scattered by a sample, and therefore can be used to analyze the back-scattered ultrasound field and derive useful information about the sample. For understanding the performance of this new transducer, angular spectrum theory is used to calculate the reflection signal which is reflected from a sample. The theoretical or predicted signal waveforms on each PVDF element are then compared with their experimental counterparts. Good agreement is observed. By observing the reflected signal waveforms, it is possible to recognize the angular refection coefficients of a sample and identify the material properties of the sample. It demonstrates the potential in non-destructive evaluation of this new analytical transducer.

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