Spectrum Analyzer Output

[teem]

Hi,

Allow me to ask a simple question that I cannot figure out.
If the input wave form to spectrum analyser is as below.
What would be the output waveform with respect to the resolution bandwith setting?
Besides, which kind of tools is easiest to go above test?
Thanks!

Best regards,

 

[betwixt]

Provided the resolution (bandwidth) is narrow enough to differentiate between the frequencies and the waveform is a sine wave, you would see a single spike in the trace that jumped from side to side as the frequency changed. If it isn't a pure sine wave, in other words it is composed of a fundamental plus some other frequencies, you would see the main spike jump from side to side with some smaller spikes around it, each representing the other frequencies or mixing products.

Depending on how fast 'T' actually is in respect of the sweep rate, the jump from side to side may visually appear as two spikes at once even though only one is really present at a time.

Brian.

 

[KlausST]

Hi,

as brian said..

And additionally you will see the switching frequency with all it´s overtones as original frequencies and as sideband to the two peaks.

And if this is calculated with an FFT and you used a window function you will see some "arcs" instead of single peaks.


Klaus


BTW: even excel can do an FFT analysis. Just calculate the signal values and see the results.