Adaptive bias control of cascode drivers in envelope tracking power amplifier devices, systems, and methods

A wireless communication device comprising:

• a power amplifier comprising:
• a driver stage configured to receive a variable voltage supply signal, the driver stage comprising:
• a cascode gate bias circuit configured to receive a first signal that is based on the variable voltage supply signal;
• and
• a cascode amplifier stage comprising a first field effect transistor (FET) and a second FET in a stacked configuration,
• wherein the cascode gate bias circuit is further configured to adaptively convert the first signal into a bias signal for a gate of the first FET, and wherein the cascode amplifier stage is configured to receive a radio frequency input signal at a gate of the second FET and to produce an intermediate output at a drain of the first FET;
• and
• a power amplifier stage following the driver stage, wherein the power amplifier stage is configured to generate an amplified signal based on the intermediate output.

A method of operating a wireless communication device, wherein the wireless communication device comprises:

• a driver stage, the driver stage comprising:
• a cascode gate bias circuit;
• and
• a cascode amplifier stage comprising a first field effect transistor (FET) and a second FET in a stacked configuration,
• wherein the method comprises:
• receiving, by the cascode gate bias circuit, a variable voltage supply signal;
• adaptively generating, by the cascode gate bias circuit, a bias signal based on the variable voltage supply signal to lower a gain dispersion of a power amplifier comprising the driver stage and a power amplifier stage;
• receiving, at gate of the first FET, the bias signal;
• receiving, at the gate of the second FET, a radio frequency input signal;
• and
• generating a first output signal at a drain of the first FET.