Noncontiguous channel amplification with a multilevel outphasing transmitter without digital predistortion

In this paper a multilevel outphasing transmitter designed at 2.1 GHz capable of linearly amplifying noncontiguous LTE channels without requiring any additional digital predistortion is presented. After applying a static calibration to both RF branches, an ACPR performance better than −50 dBc is achieved for two 1.4 MHz LTE channels separated by 5 MHz. The number of levels will be shown to be crucial in achieving optimal linearity performance. The impact of the number of levels and the validity of the static calibration on the linearity performance is analysed.