[time-nuts] Phase modulation question

[Bruce Griffiths]

cdelect at juno.com wrote:
> Hi,
>
> I'm making some phase mod index measurements as it relates to Rubidium
> and Cesium standards.
>
> Two questions.
>
> 1. Is a Bessel table for sine wave modulated FM used for PM also?
>
> 2. Where can I find a Bessel table that has fine resolution, the ones I'm
> seeing only have large increments of Mod index. (like .25  .5 1.0 1.5
> 2.0) I need to measure in between these values.
>
> Thanks,
>
> Corby
>
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>    
The only difference between fm and pm is that for fm the carrier phase 
angle is modulated by the integral of the frequency modulation signal 
whereas for PM the modulating signal directly modulates the carrier 
phase angle. Thus the analysis is exactly the same (apart from a 90 
degree phase shift of the phase angle modulation) for both sinusoidal FM 
and sinusoidal PM.

Bruce