Why is it possible for narrowband FM and AM to have a similar spectrum?

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leoren_tm

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WHy is it possible for NBFM and AM to have similar spectra?????
 

Re: narrowband FM

A couple of lines may not sufficiently explain this issue to you but this text should:
"From Amplitude Modulation to Frequency Modulation"
**broken link removed**

Regards,
IanP
 

Re: narrowband FM

thx men.....
need more info/......
:?:
:?:
:?:
:?:
 

Re: narrowband FM

If you are after simpler explenation here it is:

The Deviation Ratio (DR) is defined as the ratio of the maximum deviation of the FM signal to the maximum modulating frequency.The DR for NBFM is restricted to values between 0.5 and 1.0. By holding the DR to such small values, only the carrier and the first sideband are of significant amplitude .. see picture below ..
When only one sideband and the carrier are transmitted, the NBFM signal occupies the same bandwidth as an AM signal ..

Regards,
IanP
 

Re: narrowband FM

how about on AM????
 

Re: narrowband FM

leoren_tm said:
WHy is it possible for NBFM and AM to have similar spectra?????
Click to expand...

both will have upper and lower side band..if you look at the expression for both AM and Narrow FM ...they will differ from each other by means "sign" ( + or -) in the expression..
yet to be explored...
 

Re: narrowband FM

Amplitude Modulation bandwidth can be considered exactly two times the highest frequency of modulation ..

Reference:
**broken link removed**

Regards,
IanP
 

Re: narrowband FM

Is it NBFM or FM it doesn't matter. Both are frequency modulation. Difference is different modulation index or simply degree of modulation. At NBFM the modulation is "weak". And in this case the spectrums of FM and AM are similar. And that is a fact. You can prove it mathematically.
 

Re: narrowband FM

CAN YOU SEND ME a mathematical solution for it?? plssssss
 

Re: narrowband FM

It looks like you have bothered to read the link that was given to you before ..
**broken link removed**
All mathematics is there ..

Regards,
IanP
 

Re: narrowband FM

ib read it!!!!!!!
but not much
 

narrowband FM

as a similarity both will have same bandwidth and number of side bands
 

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