PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

622 Practical MATLAB® Applications for Engineers

Example 6.6

Create the script fi le butt_chev that returns the magnitude and phase plots of the follow-

ing analog LPFs:

a. Butterworth

b. Chebyshev/type 1

c. Chebyshev/type 2

with the following fi lter’s specs:

1. The fi lter’s order of N = 5


2. Pass-band edge at Wp = 1 rad/s


3. Pass-band ripple of Rp = 1 dB


4. Stop-band ripple of Rs = 1 dB

FIGURE 6.49
Bode plots of H(w) of Example 6.5.

Frequency (rad/s)

Phase (in degree) To: Y(1)

Bode plots:magnitude and phase

0

10

20

30

40

50 From: U(1)

100 101 102 103 104 105

0

20

40

60

80

100

Magnitude (dB)

FIGURE 6.50
Zero/pole plots of H(w) of Example 6.5.

− 3500 − 3000 − 2500 − 2000 − 1500 − 1000 − 500 0

− 1000

− 500

0

500

1000

Real part

Imaginary part

zero-pole plot