Power amplifier with envelope injection

A device, comprising:

• an amplifier having an output, and at least one of a gate bias input and a drain supply input, the amplifier being configured to receive an input signal and output an amplified signal at the output of the amplifier;
• an input configured to receive an envelope signal, the input being connected to the at least one of the gate bias input and the drain supply input and the envelope signal being at least partially determined by an attribute of the input signal to the amplifier;
• a variable attenuator connected to the input and configured to modify an attenuation of the envelope signal;
• a phase shifter connected to the input and configured to modify a phase shift of the envelope signal;
• and
• a controller, the controller being configured to modify at least one of the variable attenuator and the phase shifter to reduce a magnitude of an intermodulation distortion product of the amplifier.

A method, comprising:

• receiving an envelope signal, the envelope signal being at least partially determined by an attribute of an input signal to an amplifier;
• modifying at least one of an amplitude and a phase of the envelope signal to reduce a magnitude of an intermodulation distortion product of the amplifier, resulting in a modified envelope signal;
• and
• supplying the modified envelope signal to at least one of a gate bias input and a drain supply input of the amplifier.