Improvements in high injection transistor noise theory and models

High injection transistor noise theory and models that more closely agree with experimental results and allow accurate high injection predictions from low injection experiment are shown. The theory and models show that the hole concentration at the collector edge of base region could be a significant factor at low frequencies and thus could account for the large correlation impedance seen in experiments. At high frequencies it is necessary to account for electron and hole contribution to base noise current. Theory and models are developed which account for both. From Shockley's Basic Component current density equations, a high injection, low frequency equivalent circuit is developed which shows that in the absence of avalanche multiplication in the collector space-charge region (to keep the base current zero), the high injection factor B and diffusion factor m are not present.