Ultra-Fast (13ns) Low Frequency/Microwave Transient Measurements, Application to GaN Transistors Characterization of Pulse to Pulse Stability

Abstract

This paper describes an on-wafer fully calibrated characterization system of GaN power transistors for the simultaneous and coherent extraction of, on the one hand, the complex envelopes of the microwave (RF) voltages and currents and, on the other hand, the Low Frequency (LF) drain current generated by the non-linearities of the measured components. The complex voltage and current envelopes at both ports of the Devices Under Test (DUT) are extracted by coherent interleaving sub-sampling followed by Digital Down Conversion (DDC) [1]. The LF drain voltage and current are simultaneously measured at the output plane of the power supplies. An AlGaN/GaN HEMT has been characterized with different periodic irregular radar burst excitations.The main originality of this work lies in the fact that the generated RF time-domain waveforms used for the excitation of the transistors have been corrected to strongly reduce the emergence of the Gibbs phenomenon [2]. Lanczos-series have already been implemented in general-purpose simulator but, to our knowledge, this is the first time that they are directly used to generate a useful excitation signal in a microwave characterization system.