High efficiency broadband linear push-pull power amplifiers using linearity augmentation

A method for improving the linearity and efficiency performance of Class AB push-pull power amplifiers is described in which the process of passive linearity augmentation is applied to correct the input signal current to the power transistors and to reduce the effects of crossover distortion, producing low intermodulation distortion products up to the 1dB compression point. The method also biases the nonconducting transistor rapidly into cutoff, improving the peak collector efficiency by 15%. A brief generalized discussion of passive augmentation theory as applied to Class A amplifiers is provided, and performace data for an example 2 waft Class AB push-pull prototype amplifier is described.