合成近场校准基阵的方法研究

本文利用单根的束控线阵来构造一个虚拟近场校准基阵，使换能器能在它的近场直接测量辐射声场特性。通过利用改进的矩阵稳定技术，解决了求解束控线阵的束控系数时最小二乘解的稳定性和实用性问题。借助计算机仿真，研究了特定线阵条件下，合成近场测量基阵（Ｓ－ＮＦＣＡ）的近场空间的平面波均匀性与线阵间的间距、线阵的工作频率之间的关系。并以小球源为阵元合成一虚拟平面ＮＦＣＡ，用它对一平面喇叭换能器的近场测量得到远场指向性，并与远场实测结果比较，得到了相当吻合的结果。

Study on a synthetic near-field calibration array

Here we study a method to determine the far-field radiation from measurements made near the transducer by the synthetic near-field calibration array (S-NFCA), using a single line array of amplitude shaded in a special way. Via the computer simulation, we have solved the problem of stable and practical shading coefficients of shaded line array. With a definite line array, we study the relations among the uniformity of near-field, space between line arrays and the frequency range. Using a spherical acoustic source as the array element to synthesize a virtual plane NFCA, we measure the far-field radiation characteristics of a plane loudspeaker transducer made in the near-field, with result agree well with that measured in the far-field in a lake.