HI > On Feb 6, 2017, at 6:36 PM, jimlux <jim...@earthlink.net> wrote: > > On 2/6/17 2:37 PM, Bob Camp wrote: >> Hi >> >> One of the most basic reasons for putting out > +20 dbm is that you >> had a spec of -195 dbc / Hz for the noise floor :) >> >> Some of these specs *are* a bit mutually exclusive. > > Sure.. And to be honest, I'm not sure that some of the folks coming up with > paper requirements for these speculative low power transmitters are aware of > that. They take dBc values from 1 Watt transmitters and assume you can meet > that with your 1 mW transmitter. > > > > Then again couldn't you cool your oscillator.. that gets the T part of the kT > down lower <grin> > > Cool that puppy down to <1K and get 25dB noise improvement, eh?
Sounds like a low cost solution :) The other proposed solution is to source the signal out of a zero ohm source. It’s not clear which one actually costs less. Bob > > > >> >> Bob >> >>> On Feb 6, 2017, at 3:19 PM, jimlux <jim...@earthlink.net> wrote: >>> >>> We're always looking for low DC power, but quiet (close in), oscillators >>> for spaceflight applications, particularly as the spacecraft get smaller. >>> >>> I was intrigued by the paper Ulrich posted which actually called out a "mW >>> RF out for mW DC in" as part of their FoM. >>> >>> Is there a list somewhere of what sort of DC/RF efficiencies are >>> possible/typical. In particular, I'm interested in topologies/designs that >>> put out low powers.. (1 mW or less). There's lots of designs that put out >>> a convenient +10dBm or +13dBm or 3.3V CMOS square wave or whatever.. but >>> sometimes, you only need to radiate a few mW (I would think the low power >>> Bluetooth/Zigbee/802.15xxxx folks have been thinking about this) >>> >>> Jim >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. >> > > _______________________________________________ > 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. _______________________________________________ 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.
