(New page: DT Fourier Transform Properties * DT Fourier Transform Multiplication x[n]y[n]\longleftrightarrow \frac{1}{2\pi} \int_{2\pi} X(e^{j\theta})Y(e^{j(\omega-\theta)})d\theta * DT Four...)
 
 
Line 1: Line 1:
DT Fourier Transform Properties
+
CT Fourier Transform Properties
  
     * DT Fourier Transform Multiplication x[n]y[n]\longleftrightarrow \frac{1}{2\pi} \int_{2\pi} X(e^{j\theta})Y(e^{j(\omega-\theta)})d\theta
+
     * CT_Fourier_Int/Diff\; \; \; (1)\frac{dx(t)}{dt} \rightarrow j\omega \Chi (\omega)\; \; \; \; \; \; (2) \int_{-\infty}^{t}x(\tau)d\tau \rightarrow \frac{1}{j\omega}\Chi (\omega) + \pi \Chi (0) \delta (\omega)
     * DT Fourier Transform Convolution x[n]*y[n] = X(e^{jw})Y(e^{jw}) \!
+
 
     * DT Fourier Transform Time Reversal \ x[-n] \longleftrightarrow X(e^{-j \omega})
+
    * CT Time and Frequency Scaling : x(at) \leftarrow \rightarrow \frac{1}{|a|}X(\frac{j\omega }{a})\,
     * DT Fourier Transform Duality F(x(t)) = X(w) \longleftrightarrow F(X(t)) = 2\pi x(-w)
+
 
 +
    * CT Differentiation in Frequencyx(t)\rightarrow j\frac{d}{d\omega}X(j\omega)
 +
 
 +
     * CT Convolution: F(x_1(t)*x_2(t)) = X_1(\omega)X_2(\omega) \!
 +
 
 +
    * CT Frequency Shifting : F(e^{jw0t}x(t)) = X(j(w - w0)) \!
 +
 
 +
F(x(t)y(t))=\frac{1}{2\pi}X(j\omega)*Y(j\omega)=\frac{1}{2\pi}\int_{-\infty}^{\infty}X(j\theta)Y(j(\omega-\theta))d\theta
 +
 
 +
     * CT Time Reversal(-t) \leftarrow \rightarrow X(-j\omega )\,
 +
 
 +
    * CT Multiplication Property Mimis VersionF(x_1(t)x_2(t)) = \frac {1} {2\pi} X_1(\omega)*X_2(\omega)
 +
 
 +
     * CT Duality Property : F(x(t)) = X(w) = 2\pi x(-w) \!
 +
 
 +
    F(x(t)) = X(w) = 2\pi x(-w) \!
 +
 
 +
    * CT Conjugate Symmetry ==Conjugate Symmetry==
 +
 
 +
if
 +
 
 +
    \ F(x(t)) = X(w)
 +
 
 +
then,
 +
 
 +
    \ F(x(t)^*) = X^*(-w)

Latest revision as of 04:40, 23 July 2009

CT Fourier Transform Properties

   * CT_Fourier_Int/Diff\; \; \; (1)\frac{dx(t)}{dt} \rightarrow j\omega \Chi (\omega)\; \; \; \; \; \; (2) \int_{-\infty}^{t}x(\tau)d\tau \rightarrow \frac{1}{j\omega}\Chi (\omega) + \pi \Chi (0) \delta (\omega) 
   * CT Time and Frequency Scaling : x(at) \leftarrow \rightarrow \frac{1}{|a|}X(\frac{j\omega }{a})\, 
   * CT Differentiation in Frequencyx(t)\rightarrow j\frac{d}{d\omega}X(j\omega) 
   * CT Convolution: F(x_1(t)*x_2(t)) = X_1(\omega)X_2(\omega) \! 
   * CT Frequency Shifting : F(e^{jw0t}x(t)) = X(j(w - w0)) \! 

F(x(t)y(t))=\frac{1}{2\pi}X(j\omega)*Y(j\omega)=\frac{1}{2\pi}\int_{-\infty}^{\infty}X(j\theta)Y(j(\omega-\theta))d\theta

   * CT Time Reversal(-t) \leftarrow \rightarrow X(-j\omega )\, 
   * CT Multiplication Property Mimis VersionF(x_1(t)x_2(t)) = \frac {1} {2\pi} X_1(\omega)*X_2(\omega) 
   * CT Duality Property : F(x(t)) = X(w) = 2\pi x(-w) \! 
   F(x(t)) = X(w) = 2\pi x(-w) \! 
   * CT Conjugate Symmetry ==Conjugate Symmetry== 

if

   \ F(x(t)) = X(w) 

then,

   \ F(x(t)^*) = X^*(-w)

Alumni Liaison

Sees the importance of signal filtering in medical imaging

Dhruv Lamba, BSEE2010