Abstract: Apparatus and methods for dual loop power amplifier digital pre-distortion systems are disclosed. In certain implementations, a dual DPD system includes a first digital pre-distorter (DPD) and a second DPD. A digital IF upconverter electrically coupled between the first and second DPDs separates the DPD system into independently controlled fine and coarse sections. The adaptive adjustment processor can be used to modify or pre-distort input signals in order to compensate for the power amplifier nonlinearity. It also controls the fine DPD section to correct an RF output signal single-band adjacent channel leakage ratio (ACLR), while it controls the coarse DPD section to correct an RF output signal dual band intermodulation distortion (IMD).