采用复解析带通滤波器进行选带细化谱分析的原理为：构造复解析带通滤波器——对时域信号隔D(细化倍数)点或2D点进行复解析带通滤波——移频——进行FFT和谱分析。与传统复调制细化谱分析相比，由于只对细化选抽点进行移频，大大节省了内存空间，减少了计算工作量；由于先选抽滤波后移频，避免了较复杂的频率调整过程；复解析滤波器的负频率部分幅值为零，能够大大降低对数字滤波器特性的要求，提高细化分析的最大倍数和细化谱分析的精度。仿真研究表明，采用FIR一级数字滤波器，当半阶数为500时，最大细化倍数可达150，仍能保证幅值分析精度误差在1%以内，采用二级FIR滤波器，最大细化倍数可达2000倍以上。%The principle of multiple modulation selected band Zoom analysis using multiple analytical band-pass filter is： constructing multiple analytical band-pass filter—shifting frequency—making FFT and spectrum analysis． It can save memory and reduce calculation amount in contract with traditional Zoom spectrum analysis since frequency shifiting is made only at the Zoom extracted points and the complicated frequency adjustment is avoided because of that the frequency shifting is performed after extraction filtering． The amplitude of negative frequency components of multiple analytical band-pass filter is zero， which can greatly reduce the demand for character of digital filter， increase the maximum multiple of Zoom analysis and improve the accuracy of Zoom spectrum analysis． It is implied in simulation that the maximum Zoom time is high to 150 while one-grade digital filter is adopted with half-exponent number of 500， and the amplitude error is under 1％． The maximum Zoom time is high to 2000 while two-grade digital filter is adopted．
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