Design of Analog Gaussian Filter Used in Roughness Measuring Instrument

According to the rational function approximation method of Gaussian filter, the transfer function of an 8-order approximation filter is obtained. Based on value of the quality factor Q of the pole of the transfer function, analog cascade circuits are determined. The optimal cascading sequence and the principle of components are given. When selecting the cut-off frequency of 400 Hz, the experiment of the circuit in frequency domain and time domain is done. The result shows that the circuit achieves the desired target.