摘要
高频超声成像具有高分辨率的优点,但其衰减速度过快导致探测深度过浅。编码脉冲压缩可以解决高频超声纵向分辨率和探测深度的矛盾。利用FPGA设计了一个线性调频脉冲的发射和实时压缩系统,通过发射大时宽-带宽积的线性调频脉冲来保证信号的能量,从而提高探测深度,在接收端通过脉冲压缩获得窄脉冲保证分辨率。实验表明,中心频率为10 MHz和50 MHz的高频超声回波信号,经过脉冲压缩以后的分辨率分别为0.3 mm和41μm,旁瓣水平分别为48 d B和37 d B,信噪比分别提高15 d B和10 d B。
The high frequency ultrasound imaging has the advantage of high resolution, but it attenuates too fast to detect more information. The detection depth by using field p coding pulse compression can solve the contradiction between the resolution and the of high frequency ultrasound. A real - time compression and transmission system of chirp is designed （FPGA） ,it will enlarge the signal energy to improve detection depth by transmitting a large time -bandwidth product＇s （TBP） chirp, and narrow pulse guarantee resolution is obtained by pulse compression at the receiving end. The experimental results show that the resolution of the high frequency ultrasonic echo signals with center frequency of 10 MHz and 50 MHz are 0. 3 mm and 41 μm after pulse compression, respectively. The sidelobe level is 48 dB and 37 dB respectively, and the SNR is increased by 15 dB and 10 dB, respectively.
出处
《电子科技》
2017年第9期8-11,共4页
Electronic Science and Technology
