"NaN" result with Chirp-Z transform and then Inverse Chirp-Z

[jul7290]

I have some troubles with the Chirp-Z Transform and the inverse Chirp-Z Transform.

Basically, I have to reproduce in LabView a Matlab code. This code applies the Chirp-Z Transform on a pulse, then multiply it with a S** signal (recorded by a PNA) and then applies the inverse Chirp-Z transform.

So I found the corresponding VIs in Labview, but I have some troubles with the inverse transform. To simplify, I have in the attached VI only the two transform, without the multiplication. But the only result I get is a array of "Nan" complex numbers...

Can someone explain me why? I looked at LabView help and examples, and tried to reproduce what they do, but it's not working with my signal.

[Misic@NI]

Hi,

i was able to reproduce your problem. Try to reduce the # of bins to about 150 and take a look to the results of the inverse chirp-z transformation.
You are getting very huge values. "NaN" in this case means, that the value couldn t be displayed because of its size.

Regards,

Matijas