Signals and Systems - Electrical Engineering

670 C H A P T E R 11: Introduction to the Design of Discrete Filters

−1 0 1

−1

−0.5

0

0.5

1

2

Imaginary part

0 0.2 0.4 0.6 0.8

0

0.5

1

|H

(e

jω

)|

|H

(e

jω

)|

−1 −0.5 0 0.5 1

−1

−0.5

0

0.5

1

3

Real part

Imaginary part

0 0.2 0.4 0.6 0.8

0

0.2

0.4

0.6

0.8

1

0 0.5 1

−5

−4

−3

−2

−1

0

0 0.2 0.4 0.6 0.8

0

1

2

3

Real part ω/pi

<H

(e

jω

)

ω/pi

ω/π ω/π

α

(ω

)dB

0 0.5 1

−4

−3

−2

−1

0

0 0.2 0.4 0.6 0.8

−2

−1

0

1

2

3

<H

(e

jω

)

ω/π ω/π

α

(ω

)dB

(a)

(b)

FIGURE 11.16

Two Chebyshev filters with different transition bands: (a) even-order filter forωp=0.47π, and

(b) odd-order filter forωp=0.48π(narrower transition band).