(Inverse Fourier transform of X(w))
 
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[[Category:problem solving]]
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[[Category:ECE301]]
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[[Category:ECE]]
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[[Category:Fourier transform]]
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[[Category:inverse Fourier transform]]
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[[Category:signals and systems]]
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== Example of Computation of inverse Fourier transform (CT signals) ==
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A [[CT_Fourier_transform_practice_problems_list|practice problem on CT Fourier transform]]
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----
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== Specify a Fourier transform <math>X(w)</math> ==
 
== Specify a Fourier transform <math>X(w)</math> ==
:<math>  X(w)=\frac{1}{4+jw}    </math>
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:<math>  X(w)=2\pi \delta\left ( w- \frac{\pi}{4}\right )+2\pi \delta\left ( w+ \frac{\pi}{4}\right )     </math>
  
 
== Inverse Fourier transform of <math>X(w)</math>==
 
== Inverse Fourier transform of <math>X(w)</math>==
 
:<math>\begin{align} x(t)&=\frac{1}{2\pi}\int_{-\infty}^{\infty}X( \omega)e^{j\omega t}d\omega
 
:<math>\begin{align} x(t)&=\frac{1}{2\pi}\int_{-\infty}^{\infty}X( \omega)e^{j\omega t}d\omega
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\\& =\frac{1}{2\pi}\int_{-\infty}^{\infty}2\pi \delta\left ( w- \frac{\pi}{4}\right )e^{j\omega t}d\omega+      \frac{1}{2\pi}\int_{-\infty}^{\infty}2\pi \delta\left ( w+ \frac{\pi}{4}\right )e^{j\omega t}d\omega
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\\& =\int_{-\infty}^{\infty}\delta\left ( w- \frac{\pi}{4}\right )e^{j\omega t}d\omega+      \int_{-\infty}^{\infty}\delta\left ( w+ \frac{\pi}{4}\right )e^{j\omega t}d\omega
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\\& =e^{-j\frac{\pi}{4}t}+e^{j\frac{\pi}{4}t}
  
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\\& =2cos\left (\frac{\pi}{4}\right ) t
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\end{align}
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</math>
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----
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[[CT_Fourier_transform_practice_problems_list|Back to Practice Problems on CT Fourier transform]]
  
  

Latest revision as of 12:44, 16 September 2013

Example of Computation of inverse Fourier transform (CT signals)

A practice problem on CT Fourier transform


Specify a Fourier transform $ X(w) $

$ X(w)=2\pi \delta\left ( w- \frac{\pi}{4}\right )+2\pi \delta\left ( w+ \frac{\pi}{4}\right ) $

Inverse Fourier transform of $ X(w) $

$ \begin{align} x(t)&=\frac{1}{2\pi}\int_{-\infty}^{\infty}X( \omega)e^{j\omega t}d\omega \\& =\frac{1}{2\pi}\int_{-\infty}^{\infty}2\pi \delta\left ( w- \frac{\pi}{4}\right )e^{j\omega t}d\omega+ \frac{1}{2\pi}\int_{-\infty}^{\infty}2\pi \delta\left ( w+ \frac{\pi}{4}\right )e^{j\omega t}d\omega \\& =\int_{-\infty}^{\infty}\delta\left ( w- \frac{\pi}{4}\right )e^{j\omega t}d\omega+ \int_{-\infty}^{\infty}\delta\left ( w+ \frac{\pi}{4}\right )e^{j\omega t}d\omega \\& =e^{-j\frac{\pi}{4}t}+e^{j\frac{\pi}{4}t} \\& =2cos\left (\frac{\pi}{4}\right ) t \end{align} $

Back to Practice Problems on CT Fourier transform



\end{align}</math>

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