A New Six-Port Based Time domain Load-pull Measurement Technique

This paper presents a new method for the measurements of both voltage and current waveforms of a microwave signal. The proposed method uses a characterized reference generator to calibrate a six-port reflectometer. This novel calibration procedure allows a six-port reflectometer to measure, in the frequency domain the amplitude and relative phase of the terms of the Fourier series associated with a periodic signal. The time domain measurements allow the detection of negative current pulses in the drain of a MESFET as well as voltage peaks that can deteriorate the gate-source junction of field effect transistors. One port measurements at a fundamental frequency at 4 GHz of a commercial MESFET operated in class F are presented.