I am looking for a nice way to calculate the FT of the following function
$f(x)=\biggl(\sum_{n=1}^{c}~a_n~e^{-\frac{i}{2}~x~b_n}\biggr)^d$,
where $d,c>0$, $a_n$ and $b_n$ are real coefficients, strictly monotonously rising in $n$ and $x$ is the free variable and $c$ might go to $\infty$.
I used mathematica to calculate it, but without specification of $d$ and when $c\to\infty$, there is no way that the programme will do it.
Any helpful ideas? Thanks!!