EE511 Day 6 Class Notes
Fourier Transform Continued
Laurence Hassebrook
Updated 9-10-03
Wednesday 9-10-03
FT continued
Evaluate a Rectangular Pulse Shape and Its FT. (see notes dated 8-29-01)
t
rect    T SafT 
T 
where
sin fT 
SafT   Sinc  fT  
fT
To plot a sinc function we need to find its null or zero crossing locations. Looking at the last
function in the above equation, the Sinc will go to zero when ever the sin() function goes to zero.
Further more, except for f=0, the denominator is always non-zero. At f=0 we have 0 divided by 0
and to evaluate this we use L’Hopitals rule such that
(LH rule)
The null locations are then
fT   ,  2 ,  3 , ...
so the solution for f is
Do a shifted two pulse example
Present the impulse train
Example: 50% duty cycle square wave
Parseval’s Theoem
Go over Table of FTs (notes dated 8-31-01)
Collect data for V2
Auto Correlation (notes dated 8-31-01)
Orthogonal Functions
FS
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