Ultra compact multi-band transmitter with robust AM-PM distortion self-suppression techniques

A power amplifier for a mobile device for amplifying radio frequency signals, comprising:

• a plurality of differential amplifier cells coupled to an output passive network;
• wherein at least one differential amplifier cell of the plurality of differential amplifier cells comprises a first pair of cascode transistors and a second pair of transistors;
• wherein the second pair of transistors comprises a smaller sized gate than the first pair of cascode transistors;
• digital circuitry configurable to power on or off at least one pair of cascode transistors;
• and
• a driver stage for generating driver signals for the plurality of differential amplifier cells.

A method for operating an apparatus for amplifying radio frequency signals having a plurality of differential amplifier cells coupled to an output passive network,

• wherein at least one differential amplifier cell of the plurality of differential amplifier cells comprises a first pair of cascode transistors and a second pair of transistors;
• wherein the second pair of transistors comprises a smaller sized gate than the first pair of cascode transistors the method comprising:
• providing bias signals to gates of the transistors;
• and
• providing a voltage bias to the gates of the cascode transistors.

User equipment or mobile communication device comprising an apparatus for amplifying radio frequency signals, the apparatus comprising:

• a plurality of differential amplifier cells coupled to an output passive network,
• wherein at least one differential amplifier cell of the plurality of differential amplifier cells comprises a first pair of cascode transistors and a second pair of transistors,
• wherein the second pair of transistors comprises a smaller sized gate than the first pair of cascode transistors;
• digital circuitry configurable to power on or off at least one pair of cascode transistors;
• and
• a driver stage to generate driver signals for the plurality of differential amplifier cells.