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正交相位法是超声多普勒技术中提取双向性血流信息的一种重要方法。由于正交信号对之间通常存在幅度和相位的不平衡，从而导致了正、反血流信息的混淆，影响了平均频率、最大频率的估计和声谱图的正确显示。本文提出的补偿方法，让其中一个正交信号通过按一定要求设计的线性滤波器，从而得到幅度和相位基本平衡的正交信号对，提高了超声多普勒系统提取双向性血流的性能
The quadrature phase method is an important method for extracting bidirectional blood flow information in Doppler ultrasound. As the amplitude and phase imbalance usually exist between orthogonal signal pairs, the confusion between positive and negative blood flow information affects the average frequency, the maximum frequency estimation and the correct display of the sonogram. The compensation method proposed in this paper makes one of the orthogonal signals pass through a linear filter designed according to certain requirements to obtain a substantially balanced quadrature signal pair of amplitude and phase and improve the performance of ultrasound Doppler system in extracting bidirectional blood flow