applications: passive filters - cairo...
TRANSCRIPT
Passive Filters I
Dr. Mohamed Refky Amin
Electronics and Electrical Communications Engineering Department (EECE)
Cairo University
http://scholar.cu.edu.eg/refky/ 1
OUTLINE
• Introduction
• Low-pass Filters
• High-pass Filters
• Band-pass and Band-stop Filters
• Double tune filter
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Introduction
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• A lowpass filter passes low frequencies and stops high
frequencies.
• A highpass filter passes high frequencies and rejects low
frequencies.
• A bandpass filter passes frequencies within a frequency band
and blocks or attenuates frequencies outside the band.
• A bandstop filter passes frequencies outside a frequency band
and blocks or attenuates frequencies within the band.
Type of the filter
Low pass 0
High pass 0
Band-pass 0 0
Band-Stop
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Introduction
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• A filter is a passive filter if it consists of only passive elements
R, L, and C. It is said to be an active filter if it consists of
active elements (such as transistors and op amps) in addition to
passive elements R, L, and C.
• For a passive filter, the maximum output amplitude is equal to
the input amplitude
• For an active filter, the output amplitude can be greater than the
input amplitude
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Passive Filters
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Low-pass RC Filter
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Passive Filters
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Low-pass RC Filter
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Passive Filters
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Low-pass RC Filter
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Passive Filters
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Low-pass RC Filter
Negative angle means that
the circuit is a Lag Network
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Example 1
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Example 2
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High-pass RC Filter
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High-pass RC Filter
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High-pass RC Filter
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High-pass RC Filter
Positive angle means that the
circuit is a Lead Network
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Example 3
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Example 4
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Band-pass Filter
0
0
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Band-pass Filter
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Passive Filters
Band-pass Filter
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Passive Filters
Band-pass Filter
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Passive Filters
Band-stop Filter
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Passive Filters
Band-stop Filter
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Passive Filters
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Band-stop Filter
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What is the Bandwidth?
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Band-stop Filter
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Band-stop and Band-pass Filters
Always valid
Valid only at resonance
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Example 5
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Example 6
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