Magnus Danielson wrote:
Hi Anders,
On 11/23/2012 04:42 PM, Anders Time wrote:
I have been using an minicircuits mixer as a phase detector for
measuring
low frequency(5-10MHz) and it is usually good enough. But when I want to
measure 100MHz the sensitivity of the mixer decreases a lot, so when
I want
to measure some really low noise 100MHz(Pascall -178dBc floor with 18dBm
out) oscillators the sensitivity is not good enough. I read in an old
article by Walls, Stein et al(Design considerations in state-of-the-art
signal processing and phase noise measurement system) that one can
use two
diodes in series in the double balanced mixer to increase the
sensitivity.
I tried this with some standard 1n5711 Schottky and the sensitivity
is now
1V/rad, but is there a easier way to do this? /Anders
Craig Nelson and friends over at NIST had a little different stab at
mixer which might interest you:
http://tf.boulder.nist.gov/general/pdf/2554.pdf
This was intended for 5 MHz, but I am sure you would enjoy reading
about it never the less.
Cheers,
Magnus
They've subsequently used it at 10MHz, 20MHz and 40MHz in regenerative
dividers.
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.
