1. Electric Circuits Chapter 7 Network Frequency Characteristics
EE141
Electric Circuits Chapter 7 Network Frequency Characteristics
School of Computer Science and Engineering
Pusan National University
Jeong Goo Kim

2. 7-1 Introduction Frequency characteristics of electrical networks
the effect of the source frequency on a network
techniques for determining the frequency response of a network
the concept of resonance
various parameters
bandwidth
cutoff frequency
quality factor
filters
lowpass filter
highpass filter
band-pass filter
band-elimination filter

3. 7-2 Sinusoidal Frequency Analysis
Frequency response (Ex. 7.1)
Output voltage
Frequency tranfer function
Equalizer

4. 7-2 Sinusoidal Frequency Analysis
General form of a transfer function
Poles and zeros
the dynamic properties of a system can be gleaned from poles.

5. 7-3 Passive Filter Networks
A simple low-pass network
voltage gain
Frequency tranfer function
Half-power(break) frequency

6. 7-3 Passive Filter Networks
High-pass filter
voltage gain
Frequency tranfer function
Half-power frequency phase

7. 7-3 Passive Filter Networks
Band-pass filter
Transfer function
Bandwidth
center frequency

8. 7-3 Passive Filter Networks
Example 7.3
center freq.
lower freq.
higher freq.
Bandwidth

9. 7-3 Passive Filter Networks
Example 7.4 (band-rejection filter, notch filter)

10. 7-4 Resonant Circuits Impednace for RLC circuit Zero reactance series
parallel
Zero reactance
at resonant frequency

11. 7-4 Resonant Circuits
Phase diagram

12. Quality factor (for series circuits)
7-4 Resonant Circuits
Quality factor (for series circuits)

13. Voltage across L and C in resonance
7-4 Resonant Circuits
Example 7.5
Voltage across L and C in resonance
Bandwidth

14. For parallel RLC circuit
7-4 Resonant Circuits
Example 7.6, 7.7
For parallel RLC circuit
source current
in resonance
Example 7.8

15. Parallel RLC circuit with current source
7-4 Resonant Circuits
Parallel RLC circuit with current source
output voltage
magnitude transfer characteristic
at frequency
half power frequency
bandwidth
Q factor

16. 7-4 Resonant Circuits
Example 7.9

17. 7-4 Resonant Circuits
Example 7.10

18. 7-4 Resonant Circuits
Example 7.10(continue)