AUTO ABSTRACTION METHOD FOR SMALL-SIGNAL MODEL OF HETERO JUNCTION BIPOLAR TRANSISTOR

摘要

PURPOSE: A method for automatically abstracting a small signal model of a hetero-junction bipolar transistor(HBT) is provided to abstract each element value of a small signal equivalent circuit by calculating a precise value regarding each capacitance between a base and a collector of the HBT. CONSTITUTION: A base resistance value is determined from a real part of the first operation formula of a Y parameter. A capacitance value is determined from an imaginary part of the first operation formula. The sum of two capacitances between the base and the collector in a low frequency region of the Y parameter. A capacitance value between the base and the collector is determined in a high frequency region of the Y parameter. A gain value is determined from the second operation formula of the Y parameter. The capacitance between the collector and an emitter is determined from the third operation formula of the Y parameter. The abovementioned processes are repeated until a difference between the result value and a measurement value falls within an error scope.