A novel four stage 200W Doherty power amplifier for DVB-T transmitter

In this paper, a novel high efficiency four-stage Doherty power amplifier architecture which is convenient for practical implementation in high power applications for modern communication and digital television standards has been proposed and fabricated. In practical verification, two push-poll LDMOS FET MRF6P3450 are used as the carrier amplifier and peak amplifiers with the transmission lines load network to form a symmetric four-stage Doherty PA. In a CW operation mode, an output power of 800W with a drain efficiency of 62% was achieved. In a DVB-T OFDM with PAR of 9.5 dB operation mode, a high drain efficiency of 52% was achieved at an average output power of 53 dBm, with ACPR measured at -30 dBc level.