An approximation to alpha of a junction transistor

In this paper, a new approximation for the frequency dependence of the short-circuit current gain of a theoretical junction triode is derived, which is a rational function of frequency and convenient to use. It is shown that the approximation is in excellent agreement with the frequency response of the theoretical expression for alpha in both magnitude and phase to above the alpha cutoff frequency. The approximation is also considered in the time domain, where it is in good agreement except for small values of time corresponding to frequencies well above alpha cutoff.