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題名 | 線性陣列換能器之波束圖型特性分析=Beam Pattern Characteristics of Linear Array Transducers |
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作者 | 羅如燕; 江支汶; 鄭建華; 游益龍; Ro, Ruyen; Jang, Chi-wuen; Jeng, Jiann-hwa; Yu, Yi-lung; |
期刊 | 中華民國音響學刊 |
出版日期 | 19981200 |
卷期 | 5:2 1998.12[民87.12] |
頁次 | 頁29-41 |
分類號 | 410.025 |
語文 | chi |
關鍵詞 | 線性陣列換能器; 波束圖型; 矩形輻射法; 相位量化誤差; 頻寬; Linear array transducer; Beam pattern; Rectangular radiation method; Phase quantization error; Bandwidth; |
中文摘要 | 超音波診斷儀探頭的主要功能為激發診斷儀之超音波與接收經待測物件散射回來 之超音波,進而利用相關軟硬體設計產生物件影像,因此探頭本身設計之優劣與診斷儀的影 像品質關係至甚。本文即是探討線性陣列換能器之聚焦特性,相位量化誤差及頻寬等參數對 超音波波束圖型之影響。利用矩形輻射法的概念,施加各個陣元不同之延遲時間及利用傅立 葉轉換,可以求出線性陣列換能器在非聚焦及聚焦時,在連續波與不同頻寬時之遠近場波束 圖型。結果顯示近場聚焦可以有效地減少半功率束寬,提高橫向解析度。頻寬的增加會降低 旁波瓣之值,有助於信號雜訊比之提高,當頻寬增加到某一程度後此效應不再有明顯之改善 。波束圖型隨著相位量化誤差量的增加而有顯著的變化,甚至完全變形,當誤差量在某一範 圍內,波束圖型無明顯之改變。本文之研究結果有助於爾後設計超音波線性換能器。 |
英文摘要 | The main purpose of the ultrasonic probe of the diagnostic ultrasound system is to excite ultrasonic waves of the ultrasound system and to receive scattered ultrasonic waves from objects under test, which in turn can be used to produce images of objects. Hence the design of ultrasonic probes has great effects on the image quality of the ultrasound system. The effects of focusing, phase quantization errors, and bandwidth on the beam pattern characteristics of linear array transducers are elucidated in this paper. Using the concept of the rectangular radiation method, adjusting the delay time of each element, and utilizing the Fourier transform, beam patterns of linear array transducers can obtained. Simulation results indicate that focusing in the near field can narrow the half power bandwidth effectively and hence improve the lateral resolution. Increasing the bandwidth of the transducer, to some extent, will reduce the side-lobe level and hence increase the signal to noise ratio. Beam patterns are affected significantly or even distorted when phase quantization errors increase. However, when the error is limited to some specified rang beam patterns do not have significantly change. These results can be used to design ultrasonic linear array transducer. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。