SPECIFICATIONS IN THE
FREQUENCY DOMAIN:
A transfer function can be represented in
the Laplace s domain OR in terms of frequency domain jω.
Basically in a transfer represented in
Laplace s domain we substitute jω for each s term in the transfer function.
Some examples:
Transfer Functions |
Laplace - s
domain |
Frequency -
jω domain |
0.1
----------
10 s + 0.1 |
0.1
----------
10 jω + 0.1 |
|
|
s + 0.1
----------
10 s + 0.1 |
jω + 0.1
----------
10 jω + 0.1 |
|
|
ωn2
-----------------------
s2*ωn2 + 2s*ζ*ωn + 1 |
ωn2
---------------------------
(jω)2*ωn2 + 2jω*ζ*ωn + 1 |
|
|
The parameters usually associated with
specifications in the frequency domain are the following:
| Bandwidth of the system |
| Gain Margin |
| Phase Margin |
|