Inverted asymmetric Doherty power amplifier driven by two-stage symmetric Doherty amplifier

A new high efficiency Doherty structure for code division multiple access 2000 1×3-FA test signal is presented. The proposed Doherty structure consists of a two-stage symmetric Doherty drive amplifier and an inverted asymmetric Doherty power amplifier. This Doherty structure can improve the efficiency characteristic and reduce the amplifier's dimensions. Also, higher-order intermodulation distortion products can be self-compensated. For demonstration of the amplifier's performance, a 74 W Doherty amplifier has been simulated and measured.