筛选器基础知识： 消除锯齿

摘要： 在采样的数据系统中，超过一半采样率"别名"(改变) 到感兴趣的频段的频率分量。大多数情况下，消除锯齿的不良副作用，所以"取样不足"更高的频率只是筛选之前的 A/D 阶段。但有时，欠采样是故意，消除锯齿会导致 A/D 系统作为一个混音器功能。

Maxim > App Notes > Filter circuits (analog)
Keywords: filter basics, anti aliasing, filter requirements, filtering, sampled data system Jan 11, 2002

APPLICATION NOTE 928
Filter Basics: Anti-Aliasing


Abstract: In a sampled data system, frequency components greater than half the sampling rate "alias" (shift) into the frequency
band of interest. Most of the time, aliasing in an undesirable side effect, so the "undersampled" higher frequencies are simply
filtered out before the A/D stage. But sometimes, the undersampling is deliberate and the aliasing causes the A/D system to
function as a mixer.

This application note discusses the different filtering requirements for a sampled data system. It describes aliasing and the types
of filters that can be used for ant