Diode and Transistor Self-Analogues for Circuit Analysis

Abstract

A new method of circuit analysis based on the time-scaling of actual circuits has been proposed. Audio-frequency self-analogues of microwave frequency transistors can be constructed using charge control theory, and these accurately model transistor performance in the active region. Scaling of storage times in diodes and transistors requires multiple-lump modeling. The multiple lump model developed by Linvill is reformulated here on the basis of an analogy between charge density in the semiconductor and charge density in the model, rather than between carrier density and voltage. Only two parameters, time constants corresponding to lifetime and a diffusion transit time in the semiconductor, need be specified in the reformulated model. This simplified multiple-lump model should be generally useful for device calculations. We describe a diode self-analogue which is an exact physical realization of the multiple-lump model. Separation of active and saturation region stored charges can be achieved in a transistor self-analogue, so that a single-lump model can be used for the active, and a multiple-lump model for the saturation region stored charges.