IEEE Trans Ultrason Ferroelectr Freq Control. 2014 Mar;61(3):496-504. doi: 10.1109/TUFFC.2014.2933.
Two-dimensional ultrasonic phased arrays are becoming increasingly popular in nondestructive evaluation (NDE). Sparse array element configurations are required to fully exploit the potential benefits of 2-D phased arrays. This paper applies the conformal mapping technique as a means of designing sparse 2-D array layouts for NDE applications. Modeling using both Huygens' field prediction theory and 2-D fast Fourier transformation is employed to study the resulting new structure. A conformal power map was used that, for fixed beam width, was shown in simulations to have a greater contrast than rectangular or random arrays. A prototype aperiodic 2-D array configuration for direct contact operation in steel, with operational frequency ~3 MHz, was designed using the array design principle described in this paper. Experimental results demonstrate a working sparse-array transducer capable of performing volumetric imaging.
二维超声相控阵在无损检测（NDE）中越来越受欢迎。为了充分利用二维相控阵的潜在优势，需要稀疏的阵列单元配置。本文应用共形映射技术作为设计用于 NDE 应用的稀疏二维阵列布局的一种手段。使用惠更斯场预测理论和二维快速傅里叶变换进行建模，以研究得到的新结构。使用共形功率图，在模拟中，对于固定的波束宽度，显示出比矩形或随机阵列更高的对比度。使用本文中描述的阵列设计原理，设计了一种用于钢的直接接触操作的原型非周期性二维阵列配置，工作频率约为 3MHz。实验结果证明了一种稀疏阵列换能器能够进行体积成像。
