Two-Stage High-Efficiency Concurrent Dual-Band Harmonic-Tuned Power Amplifier

The design strategies and the implementation of a two-stage concurrent dual-band (DB) microwave harmonic-tuned power amplifier (PA) are presented in this paper. The power stage and the driver stage of this circuit are designed to operate under DB class-F conditions and DB inverse class-F conditions, respectively. The proposed DB harmonic control network of the power stage is implemented by combining a composite right/left-handed transmission line and a DB biasing line with harmonic tuning. A novel DB interstage matching network is developed to transfer the optimum fundamental output impedances of the driver stage to optimum fundamental input impedances of the power stage, as well as suppress the third harmonics at two frequency bands of interest. In the nonconcurrent mode (CM), the measured output power of the two-stage DB PA achieves two peaks of 40.2 and 40 dBm at 1.62 and 2.08 GHz with the maximum power-added efficiencies (PAEs) of 71.5% and 73%, respectively. In the CM, the maximum average PAE is up to 62%. To our best knowledge, the implementation of the two-stage concurrent DB harmonic-tuned PA is reported for the first time in the literature.