A Novel Model for Digital Predistortion of Discrete Level Supply-Modulated RF Power Amplifiers

The linearization of a discrete level supply modulated RF power amplifier using digital predistortion (DPD) is investigated. The characteristics of the system are evaluated and a novel DPD model, capable of handling the switching dynamics of the system, is developed and presented. The model is tested for an RF power amplifier operating at 2.65 GHz with a 16 MHz modulated signal. It is shown that modeling the supply voltage transitions with the novel model significantly improves linearity by up to 1.6 dB NMSE and 3.3 dB in ACLR. With the novel model DPD on the supply modulated PA can achieve similar linearity as a single supply PA but with much improved PAE.