Broadband Solid-State Power Amplifier Predistortion Linearization Scheme

Recent advancements on linearizing power amplifiers using the LINC (Linearization on Non-linear Components) architecture have attracted attentions on researchers and engineers. This is primarily caused by two reasons. (1) Maturity and availability of high density and high speed digital electronics signal processing hardware (e.g. DSP or FPGA) make complex signal decomposition computation feasible for real time operation. (2) LINC architecture offers a true uncompromising solution for both linearity and efficiency on power amplifier realization. To resolve the channel imbalance and output combiner distortions issues encountered by the LINC architecture power amplifier, an efficient adaptive digital predistortion technique is proposed. The technique continuously monitors the channel signal conditions and the amplifier output signal quality in order to properly adjust the predistortion gain and phase in the channel signals. The resulting adaptive digital predistortion LINC power amplifier provides superior linearity and efficiency with practical commercial off-the-shelf components. Simulations and analysis will be performed to quantify the performance improvements resulting from the adaptive digital predistortion technique. The proposed technique is amenable to real time implementation on the DSP (digital signal processor) and FPGA (Field programmable gate array) digital hardware.