Infinite Impulse Response Filters - Introduction to Digital Signal Processing and Filter Design - page 234

Magnitude response of a elliptic lowpass filter

1.4

1.2

1

0.8

0.6

0.4

0.2

0

0 0.1 0.2 0.3 0.4 0.5

Normalized frequency

0.6 0.7 0.8 0.9 1

Figure 4.23 Magnitude response of an elliptic lowpass filter.

Magnitude response of an Elliptic Lowpass Filter

20

0

− 20

− 40

− 60

− 80

− 100

− 120

0 0.1 0.2 0.3 0.4 0.5

Normalized frequency

0.6 0.7 0.8 0.9 1

Figure 4.24 Magnitude response (in decibels) of an elliptic lowpass filter.

Example 4.12

%MATLAB Script to design a Chebyshev I (Equiripple) Bandpass
%

filter with Ws1 = 0.25, Wp1 = 0.3, Wp2 = 0.4 ,Ws2 = 0.45,

% Rp = 0.5, Rs = 50

[N,Wn]=chebyord([0.3 0.4],[0.25 0.45],0.5,50);