FM and Bessel functions

Status
Not open for further replies.

fran1942

Junior Member level 3
Joined
Mar 16, 2012
Messages
30
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,520
Hello I am doing some experiments with FM modulation.
I have an RF generator connected to a function generator and a spectrum analyser.
I have been adjusting the modulation index and measuring the amplitudes of the side frequencies.

My question is: why is there a discrepancy between my measured side frequency amplitudes and the results I get from the Bessel function table ?
I know there is a fundamental reason for this but I am unsure what it is.

Thank you for any help.
 

May be your function generator or rf generator are not making pure sine wave. Sine wave with harmonics.
 


Are you sure that the parameter you have called "modulation index" is identical to the parameter found on the horizontal axis of the Bessel functions?
 

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…