Matt Ettus wrote: > In looking into extremely low phase noise synthesizers, I have come > across the new HMC700LP4 chip from hittite, which seems to have the > best figure of merit I have found, -227 dBm/Hz. That gives you > -107dBc/Hz at 20 kHz offset at 6 GHz according to the datasheets. > > That sounds amazingly good, but my R+S signal generator does better. > Do they use a different sort of architecture? Do they not use > conventional dividers? Some other sort of phase detector? > > Thanks, > Matt
Matt, They usually use a microwave mixer heterodyning against a harmonic multiplier driven by the reference frequency, producing an IF in the 30-50 MHz area. Often there will be a dual loop PLL to improve performance. _______________________________________________ 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.
