A reconfigurable in-band digital predistortion technique for mmWave power amplifiers excited by a signal with 640 MHz modulation bandwidth

In this paper, a novel in-band digital predistortion (I-DPD) technique with a reconfigurable coefficient pyramid is proposed to linearize a mmWave power amplifier excited by a modulated signal with very large bandwidth, such as 640 MHz. This method can overcome the multiple bandwidth regrowth issue in conventional DPD operation that normally places a burden on the 5G applications. By employing a coefficient pyramid, the proposed method can efficiently select the necessary core functions to build the nonlinear kernels according to the operation modes, which can largely reduce the power consumption and thus increase the system efficiency. Experimental results with 640MHz modulated signal proves that extending the DPD capability into the forthcoming 5G is possible.