[time-nuts] Close-in phase noise question...

[Stan W1LE]

Hello Brian,

I hope you and yours have the very best of this Holiday Season.

My considerations would be similar to spurious free dynamic range,
keeping all discrete intermodulation products very low, which
would in turn keep the intermodulation noise very low.

When you drive an amp towards and into saturation, to get harmonics 
generated,
 the broadband noise floor will be raised with intermodulation noise.

Most of the time this intermodulation noise is not a limiting factor,
until very high harmonic multiples are needed.

Stan, W1LE   FN41sr    Cape Cod


wa1zms at att.net wrote:
> Looking for comment here...
>
> The background:
> I'm working on a sub mm-wave LO chain for
> a ham radio application. While chasing issues
> of close-in phase (ie: within 1KHz of RF
> carrier) by peeling the "layers of the onion",
> I'm starting to question the performance of
> the MMICs that are used as buffers and amps
> following my Wenzel reference OCXOs.
>
> Question(s):
> Should any MMIC be allowed to be driven
> close to compression or into compression
> when striving for best close-in noise?
>
> I know and have seen the NF of a MMIC
> degrade while in compression, but my
> target right now is close-in noise rather
> than broadband noise.
>
> My design, in summary, takes 5MHz up to 630GHz
> via several multipliers and PLL stages.
>
> -Brian
>
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>