Nonlinear measurement of non periodic pulse train with mixer based NVNA dedicated to radar power amplifier

A measurement of time domain waveforms using a commercial two ports mixer based NVNA to measure a non periodic repetitive radar pulse train as a periodic one was performed. Then for the first time a 20 GHz six port mixer based NVNA able to measure three different frequencies at the same time is designed and validated. This instrument allowed us to overcome the imprecision caused by the sequential measurements of the different tones that arise when the device under test present a highly unstable pulse to pulse behavior which is common in radar functioning conditions. It was possible to catch the non linear behavior of a device within a truly non periodic predefined pulse train. The measurements are performed on an S-band 5W GaN on silicon HEMT.