Radio Frequency Domain Digital Pre-Distortion

Digital pre-distortion (DPD) systems are often used to improve the linearity of a power amplifier in transmitters. These DPD systems are typically implemented in baseband (prior to modulation). However, ever increasing signal bandwidth requirements limits the practicality of DPD systems implemented in baseband. A DPD system in the radio frequency (RF) domain (as opposed to in baseband) can solve this problem and further improve a DPD system's ability to correct for distortions. The RF domain DPD system is upstream from a digital-to-analog converter, and performs DPD after a baseband signal is up-sampled into the RF domain (after the modulation process). When compared against a baseband DPD system, the RF domain DPD system can handle significantly wider bandwidth, and has an improved ability to linearize a wide variety of distortions present in the spectrum.