A Digital RF Transmitter With Background Nonlinearity Correction

This article describes a new digital transmitter architecture that automatically corrects static and dynamic nonlinearities with no need for digital predistortion or adaptation. We draw upon the Newton-Raphson method of solving equations and show that it leads to Delta Sigma modulation as a special case and to a compact, efficient transmitter in the general case. A complete transmitter realized in 28-nm CMOS technology achieves an overall efficiency of 50% while delivering +24 dBm with an adjacent channel power ratio of -35.4 dB and a receive-band noise of -150 dBc/Hz.