Analysis of Drift Transistor Current Gain with Application to Distributed RC Networks

摘要

The common-emitter short-circuit current gain of the intrinsic graded base transistor is analyzed using the Factor Theorem of Weierstrass. The Factor Theorem permits the description of the gain function in terms of its low frequency value, i.e., the d-c current gain and the poles and zeros of the function. The analysis of this report has a two-fold purpose. The primary purpose is to show the applicability of the Factor Theorem to the analysis of network functions typical of those encountered in integrated circuit structures. For this purpose the gain functions of drift transistors have been analyzed in detail and their similarities to passive distributed RC network functions are noted. The second purpose of the research is to develop techniques for determining the steady-state and transient response of distributed active (or passive) networks in a simple manner without resorting to computers. For the calculation of these quantities the concept of an effective dominant pole and an excess phase factor is shown to be extremely useful. The effective dominant pole and the excess phase factor are derived directly in a systematic manner from the product expansion form. (Author)