Time domain <==> Frequency domain: time-varying example...

Example #1: sum of sinusoids

Continuous-time waveform 
[Graphics:../Images/index_gr_10.gif]

[Graphics:../Images/index_gr_11.gif]

[Graphics:../Images/index_gr_12.gif]
Fast Fourier Transform (FFT) 
[Graphics:../Images/index_gr_13.gif]
[Graphics:../Images/index_gr_14.gif]
[Graphics:../Images/index_gr_15.gif]

[Graphics:../Images/index_gr_16.gif]

Example #2: time-varying sinusoid

Analog waveform 
[Graphics:../Images/index_gr_17.gif]
[Graphics:../Images/index_gr_18.gif]

[Graphics:../Images/index_gr_19.gif]

[Graphics:../Images/index_gr_20.gif]
Fast Fourier Transform (FFT) 
[Graphics:../Images/index_gr_21.gif]
[Graphics:../Images/index_gr_22.gif]
[Graphics:../Images/index_gr_23.gif]

[Graphics:../Images/index_gr_24.gif]

Display all 

[Graphics:../Images/index_gr_25.gif]

[Graphics:../Images/index_gr_26.gif]

Converted by Mathematica      January 13, 2003