Filters_introduction_firstyearengineering.ppt

Filters

1. Introduction to Filters

2. PHASOR RELATIONSHIPS FOR CIRCUIT ELEMENTS

3. Practice Example
Obtain the transfer function Vo/Vs of the
RL circuit shown in Figure, and its
frequency response.
Let v
s
= V
m
cos ωt
Answer:
jωL/(R + jωL)
Ref:1, 2

4. RESONANCE

5. =

8. We can relate the half-power frequencies with the resonant
frequency.
The “sharpness” of the resonance in a resonant circuit is
measured quantitatively by the quality factor Q.

9. Q is proportional to the inverse of the amount of energy
dissipated in the capacitor and is directly proportional to the
energy stored in the inductor.