Investigations of a Power Combiner Amplifier with Feed Forward Linearization

摘要

The feed forward-power combiner is shown to be an attractive concept promising intermodulation cancellation even under high-drive conditions of the power amplifiers combined in the circuit, thus high efficiency combined with high linearity. In our proof of concept experiment, we verified the concept but also found that the adjustment of the circuit is critically dependent on the drive conditions and linearization is achieved only for a narrow range of drive power. A simulation of the experimental circuit is used to analyze the signals within the circuit and the main cause for the limitations is found to be the gain variation at high drive levels.