NAME:
YASIR AFNAN
REGISTRATION NUMBER: 21PWELE 5879
SUBJECT: CIRCUIT ANALYSIS 2 LAB
INSTRUCTOR: MUHAMMAD FAROOQ SIR
DEPARTMENT: ELECTRICAL COMMUNICATION
SECTION: C
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LAB NUMBER: 11
To study the frequency RC high filter pass filter
THEORY:
HIGH PASS FILTER:
A high pass filter is an electronic filter that passes signal with a frequency higher than a
certain cutoff frequency and attenuates signals with frequencies lower than the cutoff
frequency the amount of attenuation for each frequency depends on the filter design. A high
pass filter is usually modeled as linear time invariant system.
OR
We can simply define as a high pass filter is a filter which passes high frequency signal and
blocks or impedes, low frequency signals.in other words ,high frequency go through much
easier and low frequency signal have a much harder getting through ,which is why its high
pass filter,
HIGH PASS FILTER USES:
The high pass filter application mainly include the following
1- These filter are used in speaker for amplification.
2- High pass filter is used in to remove unwanted sound near to the lower end of audible
range.
3- To prevent the amplification of dc current that harm the amplifier, high pass filter are
used for ac coupling
.
4- High pass filter in image processing high pass filter are used in image processing for
sharpening the details.by applying these filter over an image we can exaggerate every
tiny part of detail in an image.
Cutoff frequency:
The cutoff frequency of a filter is the frequency at which the magnitude of the output voltage
signal drops by a factor 70%.
Can be calculated in case of RC
𝑓𝑐 = 1⁄2𝑅𝜋𝑐
And if we use the inductor
𝑓𝑙 = 𝑅⁄2𝜋𝐿
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Decibels:
Decibel is logarithmic expression used in filter application as a unit of gain or loss
.characteristic of logarithmic operation, processes involving multiplication, division are
reduced to additions and subtractions, that in many but all cases is advantageous because the
calculation is simpler.
𝑋
𝑋𝑑𝑏 = 20 log10 (𝑋 )
0
𝑋
𝑋𝑑𝑏 = 10 log10 (𝑋 )
0
This is for voltage
This is for power
Observation and calculation:
S.NO
Cutoff freq
𝑣
Av= 0⁄𝑣𝑖
𝑓𝑐
-1
40
0.04
02
50
0.57
03
70
0.72
04
4000
1
05
5000
1.1
𝑉0 Is the output voltage and VI is input voltage which should be fixed
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GRAPHICALLY:
AV
1.2
1
0.8
0.6
0.4
0.2
0
-1000
0
1000
2000
3000
4000
5000
6000
As there is some error in values this why the graph is a little bit wrong. But the behavior is
correct if we see on low frequency we have values nearly equal to zero while on rising
frequency it results in increasing the graph.
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