looking for article in EDN: Test Whether a Noise Source is Gaussian

The correct reference date seems to be: S R. Michaels, "Test Whether a Noise Source is Gaussian", EDN, 11 Dec. 1987, pp. 272-274

I am also interested in a copy.

Gerhard van den Berg CSIR

There's an easy method to do this--you use the level crossing statistics. It's in Papoulis's Statistical Signal Processing book, or you can see the method and some data in an old paper of mine,

starting on P. 1585.

Cheers,

Phil Hobbs

Page 1584 sure looks familiar ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

 Liberals suffer from ABYSMAL IGNORANCE... their genetic defect.

Yep, once you've got a good horse, ride it into the sunset. ;)

The fact that the noise coming out is Gaussian to past 7.1 sigma is a pretty good indication that there isn't much buried treasure there--it's just the shot noise.

That gizmo really worked--it could see a particle that scattered 50 photons, in a coherent background more than 10**6 times brighter, plus incoherent background (plasma glow) more than 10**8 times brighter. We licensed it to a vendor, which was then taken over by an English outfit that killed it off. Pity.

OT: We're off to Alaska on Sunday for a week--my son said, "Wait, there's something wrong here. Our family NEVER goes on cool vacations." Hopefully we'll get a chance to see Denali, at least one grizzly bear (from a safe distance hopefully), and a glacier or two. You never know about the weather up there.

Cheers,

Phil Hobbs

[snip]

I do that a lot too... I have some tricks in my bag that I've been using for 40+ years ;-)

Enjoy! We're heading to WV next week... hot and humid :-(

(For 50th High School Reunion and to celebrate my father's 90th birthday.)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
  My simulation, struggling to converge, is telling me something
    Maybe my idea of a ring of current mirrors is flawed ?:-)

That's why I want you to write a book. (Consider yourself duly nagged.)

Thanks.

Have a great trip, and I hope your dad remains feisty for many more. (Once the drinking elbow gives out, it's all downhill.)

Cheers,

Phil Hobbs

The correct reference seems to be "Test Whether a Noise Source is Gaussian", EDN, 11 Dec. 1986, pp. 272-274, S.T. Michaels.

I would be interested in a copy of the article as well.

I have posted this correction 3 days ago, but it did not show up on my server or the WEB. Sorry for any ghostly duplicates that might show up.

Gerhard van den Berg CSIR

"Gerhard" wrote:.

Hi Gerhard,

Most people who had copies probably got rid of them when the internet arrived. You might try a local library. According to the Invention Registration below, the author is S.R. Michaels, not S.T. Michaels. That would make a difference in the library search.

There is a pretty good description in the US Statuatory Invention Registration H1458. You can download the pdf with schematic and complete description. Go to

and enter "H1458".

The first item in the result is "SIGNAL AMPLITUDE DISTRIBUTION ANALYZER", by Robert A. Slack. This is the one you want.

Google Patent Search works well, except it looks like they're not completely indexed yet :-(

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

Obama, Questioned about the Presidency, it\'s "above my pay grade"

Thanks for the references. We have a reasonable science library that might have the EDN article or access to it. I have already persued patent H1458 and the excellent and interesting paper by Phil Hobbs

My challenge is to measure the degree of Gaussianicity (sounds like insanity - I prefer Gaussian or non-Gaussian) or not, of various noise sources/designs.

Many thanks for the feedback.

Gerhard van den Berg

[...]

You might be interested in work done by Terry Ritter on semiconductor noise generators.

Here's the start page:

Next page is noise measurements of zener, bipolar, led, diodes, ic's:

Next is "Analyzing Noise Generators". His comments are very true:

"Any electronics experimenter can build a noise source. Unfortunately, building a good noise source is harder than it looks. Correctly using such a source is harder still."

Check the waveform of zener noise near the bottom of the page. The plot is annotated "PCM - F:\\Noise\\NoiseWav\\zcc1.wav". It is hard to see.

He remarks "See how the waveform looks more "fluffy" on the bottom? It is possible that we are somehow clipping some of the signal."

Actually, this is the normal output of a zener noise generator. The noise is caused by micro-avalanche discharges, which reduce the voltage across the diode. This was discussed by Win and others in great detail some years ago. The solution is to combine the signals from two zeners and invert one in a differential op amp.

Next is "Statistical and Graphic Views of Noise". This is the most interesting part. He shows graphs of Amplitude vs Frequency, Autocorrelation, and Amplitude Distribution of 25 different methods:

This shows how difficult it is to make a good random noise generator.

Thanks for all the feedback. I am well aware of the excellent contribution by Terry Ritter on various issues with regard to 'generating' and 'measuring' true randomness.

My problem is that I need to measure up to 1 MHz and possibly up to 10MHz. That is why I looked into possibly of using the comparators technique. I hope using 2 to 5 ns comparators, to do the distribution sampling, might give me reasonable answers without blowing the budget. The other issue is digitising such wideband analogue noise. The experiments with the comparators might also provide some insight into employing them for that purpose.

I might still look into the SpectraPlus software and compare the results of the comparator technique with the results of the sampling and signal analysis techniques. It would also be a nice analysis tool to have for other experiments.

Gerhard van den Berg CSIR

"Gerhard" wrote: [...]

You need a really fast comparator to handle the peaks in 10MHz random noise. I've had very good results with the Motorola MC100EP16 line receiver. The device is temperature compensated, so you won't see much drift on a long test run. Here's some more info:

220 ps Typical Propagation Delay Maximum Frequency > 4 GHz Typical 200 fs RMS Jitter 4V p-p max input at 5.5V VEE A small amount of hysteresis will kill any oscillation. You need a good ground plane, very good bypassing, and very short leads. The output must be 50 ohm transmission line or coax. Use both outputs differentially to minimize ground bounce when switching.

You need two separate comparators for positive and negative peaks, so you can arrange the hysteresis so it doesn't affect the desired voltage level.

I've tried many other comparators, but none have come close to this one.