Thanks
in fact I want to know how they could write this H(f) on page 18 (**broken link removed**). They said that the frequency respons eof the S&H is a sin(f)/f where does it come from ?
Sorry I don't see...
s means freq. domain, I don't understand why the replacement of s to jw could help me. For me "jw" and "s" and "f" variables are same, they indicate frequency domain is that right ?
* replace s by jw
* Multiply numerator and denumerator with exp(jw*Ts/2)
* Apply EULER's formula for complex numbers to transfer the exponential function into a trigonometric function (sinus).
*This results in the expression
A(jw)=|A(x)|*exp(-j*x) with |A(x)|=sin(x)/x and x=w*Ts/2.
Thus, you have a sinx/x function with phase shift.