Linearization Approach for 5G Millimeter-Wave N-Array Beamforming Device

Implementation principles are proposed, and a comparison of linearization solutions is presented for beamforming antenna arrays driven by multiple power amplifiers. The implementation of the feedback portion in a digital predistortion (DPD) system for an array of power amplifiers (PA), which are configured to operate either as one array or as multiple sub-arrays, is shown to be critically important in determining the overall performance of the beamformed transmitter. The proposed feedback solution, based on combining the outputs of multiple PAs in a passive structure embedded in the transmitter's printed-circuit board (PCB), is shown to be effective in the realization of the DPD system of the beamformed transmitter.