Design of Wideband High-Efficiency Power Amplifier Using Transformed Radial Stubs Filtering Network Based on Extended Continuous Class-F Modes

In this paper, a design methodology for wideband high-efficiency power amplifiers (PAs) is presented, employing a transformed radial stub (TRSs) filtering network integrated within the output matching network (OMN). This approach achieves simultaneous fundamental impedance matching and harmonic control, thereby significantly improving bandwidth and efficiency. Lumped-element equivalent circuit and odd-even mode analysis are employed to analyze the transformed radial stub (TRS). In addition, extended continuous Class-F mode (ECCF) is also employed to accomplish both wide bandwidth and high efficiency in PA design. The designed PA demonstrates wideband performance and high efficiency. To validate the proposed design strategy, a ECCF wideband and high-efficiency PA is fabricated and measured. The fabricated PA achieves a 137.5% fractional bandwidth (0.5-2.7 GHz), demonstrating a drain efficiency of 58.9-81.1%, an output power of 38.5-43.1 dBm, and a large-signal gain of 8.5-13.1 dB across the band.