POKHARA UNIVERSITY
Level: Bachelor
Programme: BE
Course: Filter Design
Semester – Spring
Year
: 2009
Full Marks: 100
Pass Marks: 45
Time
: 3hrs.
Candidates are required to give their answers in their own words as far
as practicable.
The figures in the margin indicate full marks.
Attempt all the questions.
1. a)
List the advantages of Normalization in filter Design. Derive
Element Scaling equations.
8
b)
Explain Phase delay and group delay with suitable expressions.
Derive the Bessel-Thomson transfer function and corresponding
delay function for n=2.
7
2. a)
Design a filter with Butterworth response with the following
specifications.
8
Pass band attenuation: 0.5 dB
Stop band attenuation: 20 dB
Pass band edge frequency: 1000 rad/s
Stop band edge frequency: 2000 rad/s
b)
Point out the differences between Chebyshev and Inverse Chebyshev
Low pass approximation methods. Plot Chebyshev response for n=5
7
3. a)
What is the importance of Frequency Transformation? Explain low
pass to band pass transformation with suitable example.
7
b)
Explain Singly terminated and Doubly terminated LC ladder with
suitable example. Realize a 3rd order Butterworth Low Pass Filter for
singly terminated arrangement.
8
4. a)
Design an active filter to realize bilinear transfer function with zero
at 6, pole at 3 and dc gain of 1, using non-inverting opamp
configuration.
8
b)
Design a Band pass filter with a centre frequency of wo= 1000 rad/s
and a Bandwidth of 200 rad/s using Tow Thomas Biquad.The mid
band gain must be H=1.
7
1
5. a)
What is sensitivity? What is its importance in filter design? Perform
the sensitivity analysis for Sallen-Key lowpass filter.
7
b)
Consider designing a fourth order Butterworth filter with half power
frequency of wo= 200 Krad/s. The design should make use of
FDNRs. The final circuit should have elements in practical range.
8
6. a)
What is switched capacitor filter? Design a switched capacitor filter
8
b)
Draw the diagram of Tow-Thomas biquad lowpass filter, and derive
the transfer function.
7
( s  100)( s  10000)
to realize the transfer function. T ( s ) 
( s  1000) 2
7. Write short notes on: (Any Two)
a)
Higher order filter design steps
b)
Filter design technologies
c)
CMRR
2×5
2