A novel broadband Doherty power amplifier with post-matching structure

To enhance the bandwidth of Doherty power amplifiers (DPAs), a novel broadband design method of DPA, so-called post-matching structure, is proposed. The harmonics coupling between Carrier PA and Peak PA is also studied, and suppressed by utilizing harmonic short circuit. Finally, a DPA utilizing 10W GaN HEMT with post-matching structure is designed and implemented, the simulated and measured results show that the proposed DPA exhibits good broadband efficiency performance over the wide frequency range of 800MHz to 1200MHz, it achieves a fractional bandwidth of 40% with the PAE of better than 25% at 6dB back-off from the saturated power.