Transistor hybrid-π equivalent circuit under large sinusoidal voltages in the normal domain

The well known hybrid-π equivalent circuit for small-signal representation of transistors in the normal domain is extended to cover sinusoidal voltages of large amplitudes. The effective parameters obtained as the result of the exponential nonlinearities are expressed in terms of the small-signal parameters and the amplitude. Both resistive and reactive parameters are considered. The proposed equivalent circuit serves as the basis for the design of a large class of LC sinusoidal oscillators, mixers and tuned power amplifiers, and for computing the terminal parameters as functions of amplitude.