A Concurrent Dual-band Doherty Power Amplifier with Performance Enhancement Using a Novel Impendence Invert Network

In this paper, a novel dual-band impendence invert network (DBIIN) is proposed to enhance the performance of dual-band Doherty power amplifier (DPA). The designed structure is composed of a coupled line and four microstrip lines. This network can realize a perfect dual-band matching characteristic at both saturation and back-off regions with extended bandwidth, thus a better efficiency and band performance are obtained. Based on the proposed DBIIN, a 1.42/2.4 GHz concurrent DPA is implemented using two identical 10-W GaN devices. The measurement results show that the 6dB back-off (BO) drain efficiency (DE) are 61% at 1.42 GHz and 52.8% at 2.4 GHz with about 50 MHz bandwidth at each individual passband, respectively.