Analog Prototype Design :: Filter Design and Implementation (Signal Processing Toolbox)

Signal Processing Toolbox

Analog Prototype Design

This toolbox provides a number of functions to create lowpass analog prototype filters with cutoff frequency of 1, the first step in the classical approach to IIR filter design. The table below summarizes the analog prototype design functions for each supported filter type; plots for each type are shown in IIR Filter Design.

Filter Type
Analog Prototype Function

Bessel
[z,p,k] = besselap(n)

Butterworth
[z,p,k] = buttap(n)

Chebyshev Type I
[z,p,k] = cheb1ap(n,Rp)

Chebyshev Type II
[z,p,k] = cheb2ap(n,Rs)

Elliptic
[z,p,k] = ellipap(n,Rp,Rs)

Filter Type	Analog Prototype Function
Bessel	`[z,p,k] = besselap(n)`
Butterworth	`[z,p,k] = buttap(n)`
Chebyshev Type I	`[z,p,k] = cheb1ap(n,Rp)`
Chebyshev Type II	`[z,p,k] = cheb2ap(n,Rs)`
Elliptic	`[z,p,k] = ellipap(n,Rp,Rs)`

Special Topics in IIR Filter Design Frequency Transformation