Paul Burridge wrote in message . ..
On 1 Sep 2004 14:14:12 -0700, (Mike Monett) wrote:

Frequency multiplication tends to increase jitter as well as
frequency, however. To minimize jitter at the gigahertz level,
equipment builders have to start with super-low-jitter reference
oscillators. But the higher the reference frequency climbs, the
lower the final gigahertz signal's jitter.

Very interesting, Mike. By "jitter" do you mean phase noise?

Hi Paul,

Actually, I didn't write that. Those were excerpts from various
sites that discussed the pros and cons of inverted mesa crystals.

The main advantage of inverted mesa crystals is lower jitter (or
phase noise,) especially when you have to multiply to higher
frequencies such as the Ghz region. Inverted mesa crystals allow you
to start at a higher frequency, which reduces the multiplication
factor needed.

To answer your question, yes, phase noise and jitter are closely
related. Jitter is measured in the time domain and has units of
time, where phase noise is measured in the frequency domain and has
units of dBc. You can convert from phase noise to jitter by
integrating the phase noise curve.

There are many articles that discuss phase noise and jitter. Perhaps
the best are by Hajimiri and Lee:

Ali Hajimiri and Thomas H. Lee, "A General Theory of Phase Noise
in Electrical Oscillators", IEEE JOURNAL OF SOLID-STATE CIRCUITS,
VOL. 33, NO. 2, FEBRUARY 1998

http://www.chic.caltech.edu/Publicat...neral_full.PDF (441k pdf)

Thomas H. Lee, Ali Hajimiri, "Oscillator Phase Noise: A Tutorial",
IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 35, NO. 3, MARCH 2000,

http://www.chic.caltech.edu/Publicat...hase_tutor.pdf (212k pdf)

Dean Banerjee also discusses this in his book "PLL Performance,
Simulation and Design"

https://www.national.com/appinfo/wir...sBook_4_01.pdf

There is a worked example in "Measuring / Specifying Jitter in
crystal oscillators":

http://tinyurl.com/4jzfc

Wenzel has an Excel spreadsheet to calculate Allan Variance from
Phase Noise:

"This spreadsheet calculates the Allan Variance from supplied
phase noise intercepts. Total RMS jitter over the specified
bandwidth is also calculated."

http://www.wenzel.com/documents/spread.htm

Boris Drakhlis had two articles titled "Calculate Oscillator Jitter
By Using Phase-Noise Analysis," Microwaves & RF, Jan. 2001 pp. 82-90
and p. 157, but they seem to have disappeared from the web. I could
email them to you if you are interested, but they basically
duplicate the above info.

Ken Kundert also has some info on noise and jitter on his home page:

http://home.pacbell.net/kundert/

Most exciting to me is Rohde has found a way to significantly reduce
the phase noise in wideband vco's, which was previously dominated by
varactor noise. I keep searching for more information, but there
seems to be nothing in the USPTO or on the web. He sells modules but
I don't have the url handy.

Maybe some info will appear as time goes on and more people use them.

Best Regards,

Mike

On 2 Sep 2004 10:10:33 -0700, (Mike Monett) wrote:

Hi Paul,

Actually, I didn't write that. Those were excerpts from various
sites that discussed the pros and cons of inverted mesa crystals.


[excellent references snipped]

Thanks, Mike. That lot ought to keep me quiet for a while!

p.


--

"What is now proved was once only imagin'd." - William Blake, 1793.

Paul Burridge wrote:

[excellent references snipped]

Thanks, Mike. That lot ought to keep me quiet for a while!

p.

Now, watch you don't get too smart! I enjoy the discussions you raise and
usually end up learning something - which is more than I can say for some
of the self-appointed experts in other newsgroups

Best Wishes,

Mike Monett