PXIe 5450 Multitone Generator Spectrum

[mbothra]

Hello,

I am trying to generate multitones using arbitrary waveform option on PXIe 5450. I referred the example Fgen Multitone Waveform.vi. The way I understand it is that you can generate a multitone waveform at the desired sample rate and some number of samples. This waveform is then sent to 5450's memory and then it generates the signal by repeating it over time.

The problem I am having is that the spectrum of the generated signal isn't as pure as I get with the standard waveform generator on the 5450. I see lot of spectral leakage that changes with number of samples and the signal frequency.

What is the impact of number of samples ? I tried coherent sampling, but that didn't help either.

Thanks

Mayank

[levitt2me]

Hello mbothra!

How are you measuring this spectral leakage?  What did you see and what did you expect to see?

Also, it would be more beneficial to you to post this in the Signal Generators feed to get a better response on the issue at hand.

I hope this helps!

Casey L.

Applications Engineer

[mbothra]

I plot the FFT to see the spectrum. In the FFT there are bins near the fundamental frequency which have a good amount of power and I don't expect to see them. The spectrum is pretty good when I use the standard waveform generator.

I will post this on the signal generators forum.

Thanks

Mayank