A wideband digital pre-distortion platform with 100 MHz instantaneous bandwidth for LTE-advanced applications

In this paper, a digital pre-distortion platform is designed for linearization of wideband power amplifier with nonlinearity and memory effect. The proposed platform consists of digital signal processing (DSP), field-programmable gate array (FPGA), analog to digital converter (ADC) and digital to analog converter (DAC) which are all operating under a high speed of 400MHz. The platform covers a frequency band from 1.9 GHz to 3.5 GHz and supports a bandwidth up to 100 MHz PTE-Advanced application. Experimental validation is carried out on a 1.95 GHz Gallium-Nitride(GaN) Doherty power amplifier (DPA) driven by a LTE-Advanced signal with bandwidth of 100 MHz and peak-to-average power ratio(PARP) of 9.8 dB. The testing DPD results show that adjacent channel leakage ratio (ACLR) reaches -50 dBc with about 15 dB improvement.