256阵元高强度聚焦超声相控阵系统误差与多焦点模式精确控制

对一种256阵元中心开孔凹球面二维相控阵合成三维多焦点声场进行了系统的误差分析,总结了阵元激励信号的幅度和相位误差对声场参数的影响规律,为上百阵元相控阵驱动控制提供了设计容差依据.分析表明:上百阵元相控阵在声场合成能力方面具有很强的鲁棒性,5位相位量化精度足以保证合成声场的有效性,误差主要影响声场焦域能量的分布,通过提高相控阵发射总声功率等途径降低幅度误差百分比可以有效减弱固定方差的幅度误差的影响.

System errors of a 256-element high intensity focused ultrasound phased array and precise control of multi-focus patterns

A comprehensive error analysis is carried out for a 256-element annular spherical-section phased array when used for synthesizing three\|dimensional multi-focus acoustic fields. The influence of array excitation errors on field patterns is summarized for both amplitude and phase errors. References to the design of driving module are provided for phased array with hundreds of elements. The simulation results show that the phased array with hundreds of elements has a robust ability of acoustic field synthesizing. Five-bit digitalization of phase signal can ensure the validity of the abstained acoustic fields. The array excitation errors affect the focal energy distribution mostly. The effect of amplitude errors can be weakened by reducing the error ratio through increasing the overall excitation energy.