The Laplace Transform of the Dirac's comb
+inf +inf Sum d(t - n*T) is 2*Pi/T Sum d(s/j - 2*Pi/T) -inf -infI unsuccessfully tried to find the steps between the function and its transform via two paths.
First, since the Dirac's comb is an infinite sequence of Dirac's impulses, some advanced before t=0, and others delayed after t=0, the delay theorem comes to the mind. Moreover, the Laplace Transform of the Dirac's impulse being 1, it could not be simpler!
... + exp(-2*s*T) + exp(-2*s*T) + exp(0*s*T) + exp(1*s*T) + exp(2*s*T) + ...
Oops! This series does not converge in the normal sense. It should converge in the sense of distributions, but I do not know how to handle it. :-(
Second, I start from the definition of the Laplace Transform.
+inf +inf Integral Sum d(t - n*T) exp(-s*t) dt -inf -infI change the order of the sum and the integral.
+inf +inf Sum Integral d(t - n*T) exp(-s*t) dt -inf -infSince the Dirac's impulse differs from 0 only when t=n*T and has an «area» of 1, I can drop the integration. +inf Sum exp(-s*t) dt -inf
Alas! I fall in the same dead-end as I fell above!
Could you help me find the way?
Thank you very much in advance.