Compact Multi-band Digital Predistortion for RFDAC-based Single-chain Multi-band RF Transmitter

Compact multi-band RF transmitter solution will play a unique role in the forthcoming 4G-beyond and 5G wireless networks. The emerging RF class data convertor, i.e., RFDAC enables a promising single-chain multi-band RF transmitter solution. In order to combat the imperfections of practical nonlinear power amplifiers in the single-chain multi-band RF solution, we need multi-band RF signal conditioning unit. In this paper, we present a very compact multi-band digital predistortion (DPD) solution using only one under-sampling ADC and a passive band-pass filter to replace the conventional DPD feedback path. The exper-imental results verified the proposed compact multi-band DPD architecture. Preliminarily the proposed DPD scheme with a sin-gle ADC at 76.8MSPS sampling rate in the feedback path was able to provide satisfactory multi-band linearization in the single-chain multi-band RF transmitter with 1GHz bandwidth.