Design of High-Efficiency Concurrent Dual-Band Power Amplifier Based on Baseband and Harmonic Load Impedance Control for Wireless Communication

The concurrent performance of a dual-band power amplifier (DBPA) is significantly influenced by baseband and harmonic load impedances. This paper presents a design methodology for high-efficiency concurrent DBPAs by controlling baseband and harmonic load impedances. An output matching network (OMN) that incorporates baseband and harmonic impedance control circuits is proposed to realize concurrent DBPAs. This OMN provides the active device with low baseband and third harmonic impedances, while simultaneously ensuring a high second harmonic load impedance. A 1.8/2.6 GHz concurrent DBPA is implemented in this paper. When evaluated using a single-tone continuous-wave (CW) signal, the fabricated PA exhibits an output power of 42.5 dBm and 41.8 dBm with drain efficiencies (DEs) of 74.2% and 77.8% at 1.8 and 2.6 GHz, respectively. Moreover, when the DBPA is measured using a balanced concurrent 1.8/2.6 GHz two-tone CW signal, the measured maximum output power is 39.9 dBm and the measured DE is 67.4%.