Harmonically Related Concurrent Tri-Band Behavioral Modeling and Digital Predistortion

With the increase in demands of the multi-band and ultra-wideband-based transmitters, the research interest in power amplifiers (PAs) is moving toward the designing of multi-band and ultra-wideband PAs. This leads to unprecedented challenges, such as the possibility of multiband transmission at harmonic frequencies. This brief investigates and presents the novel digital predistortion (DPD) models for linearization of a previously uninvestigated case of concurrent tri-band PA at harmonic frequencies. This brief analyzes the intermodulation terms which are producing harmonic distortions and proposes 3-D harmonic memory polynomial (3D-HMP) and harmonic volterra spline (3D-HVS) models for mitigation of in-band harmonic, cross-modulation, and intermodulation distortions. The results show that the proposed 3D-HMP and 3D-HVS DPD models have linearization performance in terms of adjacent channel power ratio below -50 dBc.