A Quadrature Class-G Complex-Domain Doherty Digital Power Amplifier

摘要

An efficient digital quadrature power amplifier is presented. It shows a good system efficiency (SE) at back-off, demonstrating four efficiency peaks with the combination of a dual-supply Class-G and complex-domain Doherty (CDD) in the IQ plane. The proposed digital quadrature transmitter in 65-nm CMOS demonstrates 27.8-dBm peak output power (P_out) with a peak SE of 32.1%. For an 802.11ax 40-MHz (20-MHz) 1024-QAM OFDM signal with 13.1-dB (12.4-dB) peak-to-average power ratio (PAPR), it demonstrates an error vector magnitude (EVM) of -42.0 dB (-43.3 dB) at an average P_out of 14.7 dBm (15.4 dBm). The average SE measured with a 20-MHz single-carrier 1024-QAM signal with 6.8-dB PAPR at 21-dBm P_out is 18.4%.