NORTHWESTERN UNIVERSITY
Department of Electrical and Computer Engineering
ECE-221 Fundamentals of Circuits
WORKSHEET FOR LAB 7: FILTERS
1: Theory
1.a.1
Attach your PSPICE plot of H a ,dB ( )
1.b.1
Solve for the poles and zeroes of Hb(s). What do the poles and zeroes tell us
about the behavior of H b ,dB ( ) ?
Answer 1.b.1
1.b.2
Attach your PSPICE plot of H b ,dB ( )
2: Experiment
H a ,dB ( )
2.1
Frequency Response of Filter (a)
H(s) (dB)
0
-2100
600
1100
1600
2100
2600
3100
3600
4100
-4
-6
-8
-10
Frequency (Hz)
ECE 221 Lab 7 Worksheet
<Your Name>
Page 1
2.2 H b ,dB ( )
H(s) (dB)
Frequency Response of Filter (b)
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
100
2100
4100
6100
8100
10100
12100
14100
16100
18100
Frequency (Hz)
3: Analysis
3.1 Comment on the degree to which your theoretical and experimental results are in
agreement. What do you think are the most significant sources of error? What
properties of these two filters have we not investigated that have a significant
effect on their performance? What is a desirable state for these properties to
ensure optimum filter performance?
Answer 3.1
ECE 221 Lab 7 Worksheet
<Your Name>
Page 2