Tuned Power Amplifiers

Much of the behavior of "class C" amplifiers can be understood in terms of the response of a tuned circuit to a train of periodic current pulses. The harmonic distortion and ideal efficiency of an amplifier can be predicted from pulse shape and duration, or from an equivalent pulse duration without regard to shape. For transistor amplifiers, a simplified "charge control" model provides an estimate of the signal input power required to produce a specified train of current pulses. In this way, power gain is formulated, and the (theoretical) performance of amplifiers and frequency multipliers is compared.