Talk:Shot noise
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i thought shot noise was to do with electrons passing over a junction between two different conducting materials? ill go else where and check... mark_metcalfe@hotmail.com
I think that's called a flicker noise... kuevis@hotmail.com
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[edit] nature of shot noise
Hi,
You are absolutely right, and this page needs some editing. I think I or someone with more detailed knowledge should do this.
Briefly speaking, the granular nature of charge is not responsible for shot noise by itself. Shot noise occurs when charge carriers must cross a junction.
So for instance, a copper wite carrying current will exhibit only thermal noise but not shot noise, while a semiconductor junction will exhibit both.
Flicker noise is an altogether different phenomenon, and while there are several theories and models regarding flicker noise, there is no universally accepted physical model to explain it yet (perhaps a Nobel Prize waiting for someone), despite and perhaps owing to its universal nature. It is seen in phenomena from microscopic scale to the astronomical scale.
Vivek vivkr .at. yahoo . com
I belive you are rong. Shot noise occours in copper wires. Some discussion could take place due to the less deffined position of electrons in copper, but this only reduces the bandwith of the noise and not the its power.
I belive flicker noise is usually due to electron traps in the potential barrier beetwen conductors and isolators.
--Paclopes 19:37, 18 January 2007 (UTC)
According to Horowitz and Hill (2nd eddition) There is less than the expected shot noise in resisotrs and other conductors. (how much less is not specified) This is becasue the electrons in a conductor are coorelated, (I assume by the electric field), when an electron leaves on end of the conductor the other electrons "know" about it. For PN junctions the charge carriers move by diffusion, they are uncoorelated and show shot noise. I find the case of photon noise to be more confusing. All light sources have shot noise, but there can be excess noise from an incoherent light source (light bulb) under certain rather extreme conditions See Hanbury-Brown and Twiss Gherold 18:25, 9 February 2007 (UTC)
[edit] shot and thermal noise
Shot noise is directly dependent on current while thermal noise is indepedent of the applied voltage or current, they don't seam to be related.
[edit] references on noise
Hi,
I forgot to post some references at the end of my mail. I am adding these here. There are bound to be many sources on the web too, which are more accessible to those who are not electrical engineers or have a good library nearby.
Ref. 1 has an excellent introduction on this topic in the Chapter on Noise, (Chap. 10). Ref. 2 is also decent, although their treatment of flicker noise is not perfectly satisfying, even if it is technically correct.
1. "The Design of CMOS Radio Frequency Integrated Circuits" by Thomas H Lee, Cambridge University Press.
2. "Analysis & Design of Analog Integrated Circuits" by Gray, Meyer, Hurst & Lewis, John Wiley & Sons (Chap. 11).
There exist many more references of course ...
Vivek
[edit] examples at top
Say at the top how shot noise might mess up one's life or experiments. --Jidanni 2006-04-16
[edit] formulas
Why there are no formulas for shot noise?! The page is only talk.... Somethink like
[edit] Merge Photon noise into this article
Agree PAR 03:43, 5 November 2006 (UTC)
Agree Dr Lind 12:34, 20 December 2006 (ETC) (Shot noise being the more common term)
[edit] Deletion of content
Can someone fact check these edits? I don't understand the changes that were made or why some of the content was deleted. — Omegatron 00:59, 15 November 2006 (UTC)
- Hmmmm! I suggest we revert pending me finding my book on Noise ! 8-)--Light current 01:48, 15 November 2006 (UTC)
