Test structures for HF characterization of fully differential building blocks

A procedure is described which allows us to characterize fully differential building blocks as a linear 4-port. A new set of linear differential hybrid parameters is presented which are well suited to describe fully differential amplifiers. A measurement setup is described which allows us to determine the differential h-parameters from measured S-parameters obtained with a 2-port test set. Measurement results of a 400 MHz fully differential amplifier are presented which demonstrate the new measurement procedure.