Luis Cupido wrote: > Bruce, tks for your reply. > > > The latest spectrum analyser offerings from Agilent have similar phase > > noise floors for both the millimeter wave and low frequency spectrum > > analysers. > > Yes, but kind of puzzles me a bit since I would > be expecting phase noises more than 10x worst on a > SA covering DC to 1GHz (+/-) > (since the LO for this is an YIG oscillator circa 3GHz locked to a > reference) > comparing with an FFT analyzer that uses a few tens MHz sample rate. > > Assuming similar 10MHz reference oscillator the SA > gets it multiplied by 300 while a low freq SA (preferably FFT) > gets it multiplied by 10 maximum. > How can they claim similar performance ?! > --- > > Ok on the rest, tks. > > > Luis Cupido. > > > Luis
Perhaps the local oscillator isn't the limiting factor for the low frequency analysers. The claimed noise floor is in the vicinity (within 10dB) of -120dBc/Hz for the analysers for which I checked the specs. If the 10MHz reference has a phase noise floor of around -160dBc/Hz this is only degraded by 50dB or so to -110dBc/Hz when multiplied by 300. The YIG oscillator phase noise floor may perhaps be a little better than this. However, since state of the art ADCs have a phase noise floor of around -150dBc/Hz one would expect a lower phase noise floor from the lower frequency spectrum analysers. Surely there's an FFT based spectrum analyser out there wit this level of performance. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
