Concurrent Multiband Linearization for Power Amplifiers With Intermodulation Distortions

This letter investigates digital predistortion (DPD) models for concurrent multiband (MB) transmitters, considering intermodulations (IMDs) fully and partially overlapping with in-band carriers. In order to mitigate the issue of increasing complexity of IMD terms construction, a novel prefrequency shift MB DPD technique is proposed to translate the baseband input signals in frequency by carrier frequencies. Theoretical analysis is provided to justify the prefrequency shift technique. Experimental measurements have been carried out with a quad-band signal to validate the effectiveness of the proposed technique.