Complete Pure-Mode Balanced Measurement System

Previously, the first author has shown that the nonlinear behavior (e.g. gain compression or TOI) of some balanced amplifiers can be accurately measured using single-ended measurements: amplifiers that have a balanced stage before a non-linear stage; other amplifiers require true-mode drive to give correct differential and common-mode results. This paper describes, for the first time, a complete solution to the problem of true-mode measurements. The system and method included in this makes use of a dual-source VNA to produce either pure-differential or pure-common-mode drives in both the forward and reverse direction. A method for correcting drive signal errors due to mismatch between the VNA and the device under test is introduced, as well as a method to provide full balanced error correction to all terms. It´s remarkable that small modifications to a standard single-ended 4-port calibration provides all the required error terms.