This application note describes how the Rohde & Schwarz R&S SMW Series vector signal generators and R&S FSW Series spectrum analyzers simplify the task of testing envelope tracking designs. The generation of waveforms with a single R&S SMW200A signal source reduces timing errors of other multibox solutions. The ability to work on synthesized or proprietary waveforms increases the flexibility to match your specific application. The integration of all measurements provided by the R&S FSW spectrum analyzer enables instantaneous feedback for digital pre-distortion to improve linearity.