High efficiency multi-mode outphasing RF power amplifier in 45nm CMOS

A high efficiency multi-mode class-E outphasing RF power amplifier with a passive combining circuit is presented. The multi-mode PA improves efficiency at lower power levels by switching ON and OFF individual branches and using Efficiency Enhancement Circuit (EEC). The proposed power amplifier is designed in 45nm CMOS technology. The PA delivers 31.6 dBm peak output power at 2.4GHz with 49.2% drain efficiency in high power single level mode. For 64-QAM LTE signal with 10MHz and 20MHz bandwidth, -57 dBc and -53 dBc ACPR are obtained in single level outphasing mode with DPD. 25% and 33% average drain efficiency are obtained with LTE signal with 6 dB peak-to-average power ratio (PAPR) in single level outphasing and AMO mode respectively.