A power amplifier system includes a transistor stack and an upper portion. The upper portion includes an LC tank. The LC tank is configured to generate selected harmonics to mitigate voltage stress and facilitate amplifier efficiency. The transistor stack includes serial connected input transistors and upper transistors. The input transistors are configured to receive an input signal and the upper transistors are configured to provide an amplifier output signal. The LC tank is configured to provide the selected harmonics to at least gates of the upper transistors.