Feedforward linearizer with reduced output auxiliary amplifier

Effective feedforward linearization of a power amplifier can be achieved without compromising performance, using an auxiliary amplifier of lower power than the main amplifier overcoming the inefficiency of the classic feedforward configuration, which employs two amplifiers of the same power rating. Reduction of the power rating of the auxiliary amplifier will lead to improved system efficiency. It is shown that the operating output power level and consequential intermodulation distortion level of the main amplifier are critical in determining the minimum saturation power level of the required auxiliary amplifier. Results of theoretical calculations and CAD simulations for the required minimum saturation power level of the auxiliary amplifier are presented and indicate close agreement.