cheb2ap

Create a normalized Chebyshev II analog lowpass prototype filter in zero-pole-gain form.

Syntax

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

Inputs

n
The filter order.
Type: integer
Dimension: scalar
Rs
The minimum attenuation in decibels in the stopband, beginning at 1 rad/sec.
Type: double
Dimension: scalar

Outputs

z
The zeros of the filter.
Type: vector
The vector length will be one less than the number of poles when the filter order is odd.
p
The poles of the filter.
Type: vector
k
The gain factor.
Type: scalar

Examples

Create a fourth order Chebyshev I analog prototype filter, with 20 dB attenuation in the stop band.

[z,p,k] = cheb2ap(4, 20)
z = [Matrix] 4 x 1
0.00000 + 1.08239i
0.00000 + 2.61313i
0.00000 - 2.61313i
0.00000 - 1.08239i
p = [Matrix] 4 x 1
-0.20565 - 0.78291i
-0.92509 - 0.60426i
-0.92509 + 0.60426i
-0.20565 + 0.78291i
k = 0.1