A concurrent dual-band doherty power amplifier

This paper proposes a novel Doherty power amplifier (PA) that realizes concurrent dual-band operation. A T-network is used to implement a dual-band impedance transformer and a phase shifter simultaneously. To prove the concept a PA is designed operating at 900 MHz and 2000 MHz simultaneously. In the experimental results, the concurrent dual-band PA achieves a drain efficiency of 39.8% with an output power of 36.9 dBm at the 5 dB back-off point from saturated output power at 900 MHz, and a drain efficiency of 41.4% with an output power of 36.2 dBm at the 5 dB back-off point at 2000 MHz. Compared to the balanced PA, the drain efficiency of the proposed PA has been approximately doubled in the entire back-off power region.