Problem using FFT in HSPICE...help

Please refer to this post
https://www.edaboard.com/viewtopic.php?p=336503#336503

The output FFT I got are not in scale in terms of frequency (X-axis), why is that?

Hi:

You should try using the command:

.FFT V(Output) START=<start time> STOP=<stop time> FMIN=<min freq in x-axis> FMAX=<max freq in x-axis>

You don't have to call for a kaiser window a rectangular would do, make sure your start time and stop time is the same as yout .tran ranges. Hope this helps

Rgds