On the estimation of power amplifier efficiency for modulated signals

This paper presents a new closed form expression for the average efficiency of power amplifiers (PA) driven by modulated signals. Based on an approximation for the PA I-V curve, the PA output power and the DC current are estimated using the probability distribution function (PDF) of the modulated signal. The efficiency as a function of transistor parameters and the bias point is estimated. The closed form values are then compared to the simulated data. It is shown that the estimated efficiency values are in agreement with the simulated ones.