Dual-Band Power Amplifier With Bandwidth Extension Based on Broadband Harmonic Control Part Dual Transmission Line

This brief presents a dual-band (DB) high-efficiency power amplifier (PA) with extended bandwidth. A novel output matching network (OMN) that integrates harmonic control into DB fundamental matching design is proposed. Bandwidth of the DB PA can be efficiently extended by the OMN presented since it can offer DB broadband harmonic control while maintaining the input impedance at DB fundamentals. By precise control of the characteristic impedance on the part dual transmission line (part-DTL) and the double shunt stub (DSS), these two structures are made equivalent to the series and parallel transmission line (TL) performance at DB fundamentals. Additionally, the part-DTL modulates the input impedance in broadband near DB harmonics to pure reactive, and the DSS optimizes the imaginary part of the input impedance at DB harmonics. For validation, a DB PA is designed and fabricated with a Cree CGH40010F GaN transistor. The fabricated DB PA features the saturated output power of 42.4 dBm and 41.7 dBm with the power-added efficiency of 73.5% and 68.4% at 2.6 GHz and 3.5 GHz, respectively. Specially, the bandwidth of the DB PA is extended to over 300 MHz and 200 MHz.