Abstract: This paper presents a method for designing concurrent dual-band high-efficiency power amplifier with a novel output matching circuit. The output matching circuit consists of a harmonic control circuit and a fundamental impedance matching circuit. The harmonic impedance of the transistor is tuned to reduce the waveform overlap between the drain voltage and the drain current. The optimum fundamental impedance of the transistor at two desired frequencies can be matched to 50 Ω by the proposed fundamental impedance matching circuit. In order to verify the feasibility of the method, a dual-band high-efficiency power amplifier working at 1.9/2.6 GHz is designed using Cree’s 10W transistor CGH40010. The realized dual-band high-efficiency power amplifier achieves the maximum power-added efficiency (PAE) of 72.5% and 67.8%, respectively, while an output power of 39.8 and 40.03 dBm is delivered by the PA at the measured frequencies of 1.9 and 2.6 GHz. The proposed dual-band power amplifier reduces the circuit complexity and provides a novel power amplifier structure for multi-mode and multi-band communication systems.