Abstract Power amplifiers (PAs) are critical components in modern phones and there are ever-increasing pressures to improve performance and lower costs. The requirements for handset PAs have evolved and are placing new, more challenging, requirements on these circuits. In this chapter, we describe the system driven considerations for PA technology selection and discuss how various circuit architectures drive semiconductor technology. Contrary to many published works that only focus on the performance aspects of the power devices we expose the reader to overall considerations for process/technology selection. Considerations such as prototype cycle, wafer cost, and turn-around time are first discussed. Detailed designer considerations such as device offerings, passive device metrics, and active device characterization are presented. Comparisons of several important device technologies are shown and the link between small-signal data and large-signal performance is explored. Finally, we discuss layout floor planning and packaging considerations.