Design of Butterworth analog filter based on Matlab

The paper described the amplitude-frequency characteristics,the design method and procedure of Butterworth analog filter to obtain real signal.Butterworth analog filter was designed based on Matlab.The paper presented the design procedure of the filter based on Matlab and analyzed the amplitude-frequency characteristics of Butterworth analog filter.Matlab program was used to draw the amplitude-frequency characteristic curve of Butterworth analog filter and realize the conversion from analog filter prototype to analog low-pass,high-pass,band-pass and band-stop filter.Through the design of analog filter prototype,high-pass filter simulation shows the effects of frequency conversion.