Energy-efficient power amplifier techniques for TD-SCDMA and TD-LTE multi-standard wireless communications

An energy-efficient concurrent dual-band Doherty power amplifier (PA) and its related digital predistortion (DPD) for TD-SCDMA and TD-LTE multi-standard wireless communications are investigated in this paper. Due to the proposed inter-modulation tuning technique, the PA efficiency and output power in concurrent operation mode are improved significantly. To alleviate the burden on hardware implementation, a low complexity two-dimensional digital predistortion (2D-DPD) is employed to compensate for the nonlinearities of the dual-band PA, the coefficients number is drasitically reduced. Experimental results show that the proposed dual-band Doherty PA achieves the output power of 38.1 dBm and the PAE of 42.1% in cocurrent mode, which could satisfy the requirement of multi-standard applications.