Methodology to Design a CCF−1 Ku Band GaN MMIC PA with Nonlinear Output Capacitance

An active second harmonic load improves the efficiency of a continuous class F inverse power amplifier (PA). Such an active load can be achieved with either an active harmonic injection or by utilizing the effect of a nonlinear output capacitance $(C_{out})$. This paper presents a methodology to achieve an active second harmonic load to the continuous class F inverse PA at the current source reference plane (CRP) with a passive matching network at the extrinsic reference plane (ERP). As a proof of concept, a continuous class F inverse PA operating at the Ku band is designed with $0.25\mu \mathrm{m}$ GaN HEMT technology from UMS. The designed PA operates from 16.5 to 17.4 GHz with a drain efficiency (DE) of 15 to 25%.