The pulse generator is the critical component in high-frequency ultrasound imaging systems. Currently, there still exist some shortcomings about commercial ultrasound image systems and devices such as 5900 PR …etc.. However, to achieve a higher sensitivity and high performance, a programmable pulser generator is desired to match the requirements of high frequency ultrasound image system. In this study, we utilized a novel bipolar pulse generator method to overcome those issues in developed high resolution image system. As the needs of application in clinic, a real –time of high-frequency ultrasound imaging systems, including pulse generator, high speed scanning mechanism, high voltage protection and FPGA trigger control circuit, was developed in our Laboratory. This paper will focus to compare the performance of the bipolar generator and unipolar generator as used in pulse generator device respectively. Finally, the developed bipolar pulse generator show the better performance than the unipolar generator does. The bipolar system can generate clean N-cycle bipolar pulses and improve the center frequency of transducer up to 60 MHz. The axial resolution of scan system has been improved to around 60 μm. In addition, the result indicated that the proposed bipolar pulser could increase 4 dB for pulse/echo waveforms amplitude.
Bipolar-power-transistor-based limiter for high frequency ultrasound imaging systems