Page 200 -

the gain curve for frequencies below the lower cutoff and higher than the
upper cutoff) through having many of these prototype filters in cascade. This
will be a topic of study in future linear system or filter design courses.

In-Class Exercises

Pb. 6.59 Work out the missing algebraic steps in the derivation leading to
Eqs. (6.123) through (6.126).
Pb. 6.60 Given the following values for the lower and upper cutoff frequen-
cies and the sampling time:

–5
f = 200 Hz; f = 400 Hz; τ = 10 s
1 2
find f and plot the gain curve as function of the normalized frequency for the
0
bandpass prototype filter.

6.10 MATLAB Commands Review

abs Computes the modulus of a complex number.
angle Computes the argument of a complex number.
conj Computes the complex conjugate of a complex number.
find Finds the locations of elements in an array that satifies certain
specified conditions.
imag Computes the imaginary part of a complex number.
real Computes the real part of a complex number.

© 2001 by CRC Press LLC