M. Vaidyanathan et Dj. Roulston, EFFECTIVE BASE-COLLECTOR TIME CONSTANTS FOR CALCULATING THE MAXIMUM OSCILLATION FREQUENCY OF BIPOLAR-TRANSISTORS, Solid-state electronics, 38(2), 1995, pp. 509-516
Expressions for the effective product (r(b)C(c))(eff) of base resistan
ce and collector capacitance for calculating the high-frequency power
gain and maximum oscillation frequency are obtained from the transisto
r hybrid-pi equivalent circuit. The expressions are shown to agree wit
h the results of circuit simulations performed using a fully distribut
ed transistor model.