Real-time non-linear de-embedding

Abstract

High-efficiency operating modes (class B, F, D, E, etc.) of RF power-transistors can only be well understood and evaluated when the voltage and current time-domain waveforms at the level of the intrinsic current-generator of the transistor are known. Large-signal network analyzers (LSNA's) allow the measurement of time-domain waveforms at the extrinsic level. This work describes for the first time real-time measurement software that controls a harmonic load-pull test-bench, thereby allowing the simultaneous evaluation of time-domain waveforms at both the extrinsic and the intrinsic level of a power-transistor. A de-embedding algorithm calculates the intrinsic waveforms from the extrinsic ones, thereby taking into account the effect of the non-linear capacitances within the transistor.