Digital predistortion of RF power amplifiers with Zhu's general sampling theorem
In this paper, the wideband digital predistortion (DPD) and the Zhu's general sampling theorem (ZGST) are applied to compensate the nonlinear characteristics of a wideband RF power amplifier with memory effects. In order to utilize the ZGST, the DPD test bench is carefully designed after analysis with the ZGST. The power amplifiers are excited by a long term evolution advanced signal with up to 100 MHz bandwidth and the memory polynomial model is chosen as the DPD mode after some modifications. The mode parameters are extracted by the standard least square method. Experimental results show that adjacent channel leakage ratio of the PA reaches about -55 dBc with over 10-dB improvement by DPD and the ZGST.