A nonlinear HEMT model for the design of frequency doubler and mixer circuits

This paper presents a nonlinear transistor model for millimeter wave HEMT devices. The model has been implemented in both parameter extraction and commercial circuit simulation software. It takes into account the nonlinearities of the gate-source and the gate-drain capacitances, and it allows accurately modeling of the transconductance as a function of the gate-source voltage. The model has been validated using a large-signal measurement system. Several nonlinear circuits comprising frequency doublers, oscillators and mixers have been designed and the measured results are in good agreement to the nonlinear simulation.