VNA based load pull harmonic measurement de-embedding dedicated to waveform engineering

This paper presents a simple methodology to observe the RF waveforms at the drain source current reference plane of the transistor, without using a complete nonlinear model. The aim is to allow Power Amplifier designers starting their work using VNA based harmonic and time domain load pull measurements, and S parameter measurements. The later measurements will be used to extract a linear model first. Then the parameters of the linear model will be used to deembed the load pull measurements directly at the voltage controlled current source plane, in order to enable waveform engineering. Because of the well know theoretic conditions that enable optimum efficiency, this methodology can also be used to avoid time consuming multi-harmonic load pull measurements. Harmonic impedances can be defined accordingly to the knowledge of the operating class addressed, while load pull optimization can be addressed to refine the fundamental matching only.