Steps to design an Analog Chebyshev Lowpass Filter

Design Steps of an Analog Chebyshev LPF:

• Find the order of the filter 'N'
• Round off the order to the next higher integer
• Obtain the values of major axis 'b' and minor axis 'a' of an ellipse
• Calculate the poles which lie on the ellipse
• Find the denominator polynomial D(s) of the transfer function using the poles
• Find the numerator polynomial N(s):
• N(s) depends on the order of the Filter:
• For N odd values, the N(s) can be obtained by substituting s=0 in the D(s)
• For N even values, the N(s) can be obtained by substituting s=0 and divide the result by 1/square root (1+e2)
• Finally obtain the transfer function of an analog Chebyshev lowpass filter by taking the ratio of N(s) to D(s)