Hi Here’s the phase noise on the 15 MHz. There are a few spurs, and an very real hump out at the likely frequency of the Lucent switcher. The 15 MHz is pretty clean compared to most /all of the other units I’ve seen on the surplus market.
I would not multiply this up to 40 GHz with a broadband multiplier. I would be quite happy to run it into a PLL with a rational bandwidth. You will beat the noise on the output with a fairly simple VHF VCXO past 100 Hz. No reason to have a bandwidth outside the 20 to 80 Hz range. Math: 15 MHz to 150 MHz -> 20 log (N) -> 20 db. -140 dbc / Hz shown below at 100 Hz offset -> -120 dbc/Hz You can get numbers better than -120 dbc/Hz at 100 Hz offset out of a number of pretty simple VHF VCXO circuits. Bert has one that seems to work fine for him. Bob
15 MHz phase noise vs ULN.pdf
Description: Adobe PDF document
_______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
