New General Formulation and Experimental Verification of Harmonic Clipping Contours in High-Frequency Power Devices

摘要

This paper presents a novel closed-form solution for the theoretical calculation of harmonic clipping contours when an arbitrary number of harmonics is considered. The clipping contours can be used to design the loads of a high-frequency power device in order to avoid drain current clipping, and hence preventing strong nonlinear effects. For the first time the predicted second harmonic contours are validated thoroughly by means of experimental characterization of GaN HEMT devices. The measured contours result in good agreement with the theory. Moreover, the effect of third harmonic load tuning is also assessed and verified for the first time. These results prove that the clipping contours can be used as a tool for the systematic design of low-distortion power amplifiers.