Towards a 15.5W Si-LDMOS Energy Efficient Balanced RF Power Amplifier for 5G-LTE Multi-carrier Applications

In this paper, a 15.5W Si-LDMOS balanced RF power amplifier has been designed using 2.620-2.690GHz frequency band to improve efficiency and linearity for 5G-LTE mobile applications. The amplifier was designed and simulated using large signal Si-LDMOS transistor model to achieve 53% PAE, 41dBm Pout, 14 dB gain at P1dB saturation point. The proposed balanced RF power amplifier was fabricated and measurement results for phase variation of the signal between the carriers have been the main focus. At 1dB compression point power added efficiency increased to 81.5% with 19.5 gain at the Pout. The AM-AM and AM-PM measured data of the balanced RF power amplifier was extracted from the MATLAB fitting tool to produce polynomials. The polynomials were used in the proposed pre-distortion technique to compensate for the nonlinearities of the balanced power amplifier. A simple linear model was designed for behavioural modelling of the memory-less baseband digital pre-distorter. A Simulink IEEE 802.11a OFDM Transceiver system was used to demonstrate validity of the proposed pre-distorter. To the best of authors’ knowledge, this study presented excellent results of pre-distortion system that compensated the nonlinearity behaviour of the balanced RF power amplifier using the Simulink version R2011a.