MODULE 3 Flashcards
CONTINUOUS-TIME FOURIER SERIES
The continuous time Fourier Series (CTFS) refers to a signal processing operation that transforms continuous time signal into discrete frequency signal.
The CTFS is used to represent a periodic non-sinusoidal signal into sum of harmonically related sinusoids.
A. TRIGONOMETRIC FOURIER SERIES
x(t)= a_0+∑(n=1)^∞▒〖a_n cos(nω_0 t)+∑(n=1)^∞▒〖b_n sin(nω_0 t)〗〗
a_0
1/t_0 ∫_T▒x(t)dt
a_n
2/t_0 ∫_T▒x(t)cos(nω_0 t)dt
b_n
2/t_0 ∫_T▒x(t)sin(nω_0 t)dt
ODD SYMMETRY
{█(a_0=0@a_n=0@b_n≠0)┤
EVEN SMMETRY
{█(a_0=0@a_n≠0@b_n=0)┤
HALF- WAVE SYMMETRY
{█(a_0=0@a_n≠b_n≠0 ∀ odd n @〖a_n=b〗_n=0∀ even n)┤
B. POLAR FOURIER SERIES
x(t)= d_0+∑_(n=1)^∞▒〖d_n cos(nω_0 t+∅_n ) 〗
d_0
〖=a〗_0=1/t_0 ∫_T▒x(t)dt
d_n
√(〖a_n〗^2+〖b_n〗^2 )
∅_n
〖tan〗^(-1) (b_n/a_n )
C. EXPONENTIAL FOURIER SERIES
x(t)= c_0+∑_(n=1)^∞▒c_n e^(j〖nω〗_0 t)
c_0
〖=a〗_0=1/t_0 ∫_T▒x(t)dt
c_n
1/t_0 ∫_T▒〖x(t) e^(-jnω_0 t) dt〗