SEMICONDUCTOR JUNCTION NOISE REVISITED: WHERE HAVE ALL THE PHYSICAL NOISE SOURCES GONE?

Abstract

The distinction between "physical" and "equivalent" noise sources in bipolar junction transistors and other semiconductor devices has become blurred in the current engineering textbooks. An unfortunate consequence of this is the emergence in the literature of fictitious noise sources such as the "the collector-current shot noise" and the "base-current shot noise". These are often assigned a physical reality and incorrectly treated as real physical noise sources, independent of circuit topology. Text-books have encouraged successive generations of students in this belief. Non-physical noise sources such as these are convenient and legitimate, even essential, for the effective modeling and simulation of circuit noise. However their naïve use in teaching and research is likely to continue to give rise to fallacious concepts and misleading conclusions. The physical. The physical modeling of the light-emitting diode, the photon transport transistor and the bipolar junction transistor are briefly discussed to illustrate this view.