New trends in characterization and modeling of High Power devices

In this paper, we present some non exhaustive measurement techniques used for characterization and modeling of high power devices. Capabilities offered by pulsed measurements can be an efficient approach to deal with self-heating effects and sometimes trapping effects encountered in microwave high power devices. Pulsed techniques allow to separate self-heating and trapping effects, making like this the modeling process easier. A pulsed RF and pulsed bias load-pull system is then described as well as a time waveform measurement system. Capabilities of these two characterization tools are illustrated with results obtained on a high power silicon bipolar transistor and on a GaAs MESFET device

Power Performance Evaluation of AlGaN/GaN HEMTs through Load Pull and Pulsed I-V Measurements

A systematic evaluation of power performances of AlGaN/GaN HEMTs has been performed by means of CW on wafer Load Pull measurements at X band. Those measurements have been correlated to the results obtained through I-V and S-parameters pulsed measurements and a strong correlation has been found between the two types of measurement. Power up to 6Watts has been measured on a 1.2 mm device that can be further improved if trapping effects can be removed. A non linear electrical model of the 0.25x 1200 µm² transistor taken from the I-V and the S-parameters pulsed measurements is validated by CW load pull measures