A Bandpass Class-F Power Amplifier Based on Terminated Coupled Lines Filter for 5G Application

This paper presents a high efficiency filter-integrated Class-F power amplifier (PA). To fulfill the requirements of high-efficiency Class-F mode, the fundamental and harmonic impedances are converted from intrinsic current generator plane to the package plane through lambda/4 transformer and other microstrip lines. Bandpass filter (BPF) based on terminated coupled lines (TCLs) is employed not only to realize output impedance matching but also to provide high-selectivity bandpass responses. To verify the proposed method, a 2.2-2.6 GHz Class-F filtering PA with high efficiency and integration has been designed, simulated and measured. The results show that the designed PA exhibits both high-selectivity bandpass responses and good PA performance with the saturated output power around 40 dBm and the maximum PAE about 58%.