High-Efficiency Broadband Extended Continuous Class B/J Power Amplifier with Excellent Flatness

In this paper, an extended continuous Class-B/J power amplifier for the 5 G band NR78 is proposed. The power amplifier (PA) is designed using a multi-branch parallel structure to realize optimal second-harmonic impedance matching within a broad bandwidth. It then employs low-pass matching techniques (LPMT) to design a low-ripple fundamental frequency matching network that enhances the gain and efficiency flatness of the PA. Simulation results demonstrate that within the $3-4 \text{GHz}$ frequency band, the output power ($\text{P}_{\text{out}}$) is $\mathbf{4 0 - 4 1} \mathbf{~ d B m}$, the drain efficiency (DE) is $60 \%-70 \%(\pm 5 \%)$ and the gain is $10-11 \text{dB}(\pm 0.5)$.