Innovations in Characterizing and Modeling Active Devices under Modulated Operating Conditions

Over the last couple of years new methods have been invented and developed to characterize and model active devices like amplifiers, mixers and frequency converters under modulated operating conditions. The combination of a vector signal generator and a vector network analyzer enables “Modulation Distortion Analysis,” a novel way to design optimal complex stimulus-response experiments to determine the linear and non-linear distortion present in active devices. Modulation distortion analysis is also available in circuit simulators. The method provides unprecedented accuracy and precision through the use of vector calibration, coherent averaging, using so-called “compact test signals” (CTS), and novel statistical processing of the acquired data. This new measurement capability is used for the extraction of behavioral models, as well as inverse behavioral models, also known as digital predistortion (DPD) models.