一种抗混叠滤波器的设计

摘要

针对信号采集时，频率混叠现象的发生，为了能够有效地提取有用信号，本文介绍了滤波器的设计原理。通过分析混叠现象产生的原因，探讨了几种常见滤波器的特点并进行了比较；最后设计了一种基于二阶巴特沃斯带通抗混叠滤波器。通过仿真结果可以得出，该滤波器具有通带衰减特性平坦，能够有效避免混叠现象发生，为工程实践提供了可靠的理论指导。%Aim at signal acquisition, the frequency alias happened regularly, in order to getting available signals, the paper introduced the principle of filters. By analyzed the appearance of the signal aliasing phenomenon;discussed and compared the characteristic of several common filters; at last designed a kind of anti-alias filter which based on 2nd order band pass Butterworth filter. The filter had a smooth band pass damping, voiding alias happened, supplied reliable theory guide for engineering practice.