1. 6. Time and Frequency Characterization of Signals and Systems
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6. Time and Frequency Characterization of
Signals and Systems
6.1 The Magnitude-phase Representation of
the Fourier Transform
For signal x(t) :

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3. 6 Time and frequency characterization of S&S

4. 6 Time and frequency characterization of S&S

5. 6 Time and frequency characterization of S&S

6. 6.2 The Magnitude-phase Representation of
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6.2 The Magnitude-phase Representation of
the Frequency Response of LTI System
System characterization:
Impulse response:
Frequency response:

7. 6.2.1 Linear and Nonlinear Phase
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6.2.1 Linear and Nonlinear Phase
Linear phase:
Nonlinear phase:
Example:
Effect: Linear phase means non-distortion
of signal transmission.

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( Linear phase )
( Original signal )
( Nonlinear phase )

9. Distortionless system: is flat.
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6.2.2 Group Delay
Definition:
Example:
Distortionless system: is flat.

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11. 6.2.3 Log-Magnitude and Bod Plots
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6.2.3 Log-Magnitude and Bod Plots
Magnitude spectrum:
Phase spectrum:

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13. 6.3 Time-Domain Properties of Ideal Frequency- selective Filters
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6.3 Time-Domain Properties of Ideal Frequency-
selective Filters
Lowpass filter:
(1) Continous time:
(2) Discrete time:

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18. 6.4 Time-Domain and Frequency-domain Aspects of Non-ideal Filters
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6.4 Time-Domain and Frequency-domain Aspects
of Non-ideal Filters
Basic parameter of lowpass filter:

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21. 6 Time and frequency characterization of S&S

22. 6 Time and frequency characterization of S&S
Problems: