A describing function approach to bipolar RF-power amplifier simulation

A method for fast and accurate computations of the primary performance parameters such as gain, efficiency, output power, and bandwidth in class-C biased RF-power amplifier stages is presented. The method is based on a describing function characterization of the RF-power transistor where the terminal currents are assumed sinusoidal. The approximation comprises both the input and output properties of the transistor simultaneously and includes the effects of base widening, current saturation, and the most significant thermal dependencies. The method is verified through a series of experiments.