Cross Correlation methods are commonly used with analog mixers.
Most of the high end commercial offerings use it (Holzworth, Anapico, Rhohde &
Schwarz, etc.)
Bruce
> On 12 December 2019 at 18:53 Gerhard Hoffmann
> wrote:
>
>
> It seems the mixer noise cannot be ignored.
>
>
> I wonder then
It seems the mixer noise cannot be ignored.
I wonder then why nobody takes the mixer to cross correlation land,
and maybe even the driver amplifier.
The FFT analyzer can do it anyway, a second AF pre amp costs nothing,
and other than that
there are only another mixer and 2 power
HI
For quite a while, the “quick and easy” way to do it has been to run one of the
Mini Circuits RPD parts into a > 5K load at audio. You get a nice big output
voltage
without a lot of crazy effort. Follow it with the highest voltage / lowest
noise op amp
you can find ….
Bob
> On Dec 11,
Hi
5V and even 3.3V OCXO’s are fairly common these days. They show up in
the catalog pages of a number of outfits and have for a decade or two.
Trimble buys OCXO’s on the open market. They have used several suppliers
over the years. The spec’s are indeed unique to Trimble, but by no means
There are a number of NIST papers on this:
https://tf.nist.gov/general/publications.htm
You can also simulate the effect of a capacitive IF port load.
However a capacitive load can also degrade the isolation and RF and LO port
mismatch.
One can also use diode connected BJTs instead if lower
Hi colleagues
In parallel to my GPSDO project I am also thinking about a DMTD measurement
system which should also be capable of doing phase noise measurements. This
will be necessary to measure the stability and phase noise of my own GPSDO.
There is the paper from W. J. Riley, "A small DMTD
