中文摘要：

基于有限衍射波束的高帧率（High frame rate，HFR）成像系统能实现快速成像，但成像区域为矩形，使得远区成像的信息量受到一定的限制；同时由于通过一次发射事件成像，信噪比较低。本文提出一种方案有效地解决了这些问题。方案采用Golay互补序列作为激励信号及两次发射与接收过程，每个发射事件同时发射两个不同角度的平面波。在对接收信号进行处理时。利用Golay互补序列良好的正交性及其相关函数为冲击函数特征，不仅显著地提高了接收信号的信噪比，而且有效地分离出相对于不同发射角度的两个平面波的回波信号。然后分别用HFR成像方法重建不同区域图像，最后合成一帧扇形成像。

英文摘要：

The high frame rate （HFR） ultrasonic imaging system, which is developed with limited diffraction beams, constructs images at a high frame rate. However the rectangular imaging area, to some extent, restricts the far field imaging information. At the same time, because of one transmission for constructing image, the system suffers from low SNR. In this paper we present a computationally efficient method to construct sector mode image and to increase the SNR in HFR system. The method uses Golay complementary sequence as excitation to realize two transmission events. Each event simultaneously transmits two plane waves with different transmission angle. Then the received echo signals related to different angle are separated according to orthogonality of Golay complementary sequence and used to construct two images of different area by HFR method. Finally the two images are synthesized to one frame of sector mode image.