数字波束合成技术是相控阵超声检测相对于其它超声检测所特有的，也是整个信号接收处理系统的核心技术。通过设计基于可编程现场门阵列(FPGA)的各个模块，充分利用FPGA的优点，实现了精确延时和快速加权求和。从而可以对回波信号在不同方向和深度进行动态聚焦，很好地实现了波束的数字合成。

Digital beam forming(DBF) is special for phased array ultrasonic transducer compared to other ultrasonic nondestructive testing and is also the kernel technology of the whole signal-receiving system. By the merits of field programmable gate array( FPGA), exact time-delay and fast adding of signals multiplied by weighting factors were achieved through modules based FPGA. Dynamic focusing of received signals in different directions and depths was also achieved. Good DBF was realized.