全通多相网络滤波器组的理论和设计

本文进一步研究了应用全通滤波器实现均匀N带滤波器组的设计理论。我们提出了一种两级全通型滤波器组的结构,第一级为周期性镜像半带滤波器,第二级为两个N/2带的带通滤波器组。第一级的阻带恰好可以抑制第二级的不可控带,实现了全通型多相滤波器的连续阻带持性。并且给出了综合滤波器组的实现方案,可以使整个分析/综合系统完全消除混叠和幅度失真。最后本文给出了一个实例。

THEORY AND DESIGN OF UNIFORM FILTER BANKS USING ALL-PASS FILTERS

The theory of uniform filter banks using all-pass filters is further developed. A filter-bank structure using two-stage all-pass filters is proposed. The pre-stage is half-band filters with period, the post-stage is two pass-band filter banks. The stopband of the pre-ttage filter just controls the don't-care band of the poststage filter using all-pass polyphase, so that a realization of continuous stopband property is obtained Moreover, a method of implementing synthesis filter banks is given, which eliminates aliasing and amplitude distortions of analysis/synthesis system. Finally, an example is listed.