Simulated Annealing Particle Swarm Optimization for a Dual-Input Broadband GaN Doherty Like Load-Modulated Balance Amplifier Design

In this brief, an automatic power amplifier (PA) design system based on simulated annealing particle swarm optimization (SA-PSO) algorithm is proposed to perform multi-objective optimization in designing broadband Doherty like load-modulated balanced amplifier (LMBA). Specifically, by combining the programming environment with commercial electronic design automation (EDA) software, the optimization process can be implemented automatically. Then, complex and rigorous impedance trajectory aligning at different power levels can be easily obtained using the proposed optimization algorithm, demonstrating the automatic PA design system’s superiority over the built-in optimizer in commercial EDA software for designing broadband Doherty like LMBA. A 2.5-3.5 GHz dual-input Doherty like LMBA is simulated and measured, showing a saturated output power of 45.4-48.2 dBm, a saturation drain efficiency of 60.7% - 69.7%, a 6 dB power back-off DE of 59.2% - 65.8%, and a 9 dB power back-off DE of 52.7% - 66.9%.