An RF/DSP Test Bed for Baseband Pre-Distortion of RF Power Amplifiers

A baseband-to-baseband test bed for characterization of RF power amplifiers and linearization algorithms is proposed. Using this system, algorithms for baseband pre-distortion may be tested in automated fashion, simulating the performance of a real-time DSP processor operating in conjunction with actual RF power amplifier circuits. Full characterization capability to 6 GHz, and up to 6 MHz of baseband bandwidth at 5X oversampling rate is available. The utility of the system is demonstrated with a GaAsFET power amplifier linearized for CDMA use at 1.9 GHz using a lookup table baseband model for amplitude and phase distortion extracted iteratively from oversampled baseband data.