In this paper, the necessity of antialiasing filtering by using antialiasing filter is demonstrated by the theory of digit signal processing of the time domain and frequency domain of input signal in signal processing device.

• 本文从信号处理设备对输入信号进行时域和频域数字信号处理的角度；论述了采用抗混滤波器进行抗混滤波的必要性.