Various embodiments are disclosed relating to wireless systems, and also relating to transmitter amplifiers, such as, for example, polar transmitter amplifiers with variable output power. According to an example embodiment, a circuit is provided including a plurality of selectable amplifier cells. Each amplifier cell may receive a phase or frequency modulated signal and an amplitude modulated signal. Each amplifier cell may output a signal based upon a combination of the received amplitude modulated signal and the received phase or frequency modulated signal if the amplifier cell is selected. The circuit may provide a variable output current or output power based upon the selection of one or more of the amplifier cells.