Waveform Engineering beyond the Safe Operating Region: Fully Active Harmonic Load Pull Measurements under Pulsed Conditions

It is often desirable to measure device characteristics under non-continuous operation, perhaps to better simulate actual operating conditions, to reduce the thermal loading or to investigate RF operation going beyond the CW safe operating region. In this paper a measurement solution is presented that allows for the concept of experimental RF waveform engineering to be undertaken under such conditions. The system is demonstrated by using it to investigate the feasibility of operating GaAs based HEMT technology under pulsed conditions in high efficiency modes that required high RF voltage swings that extend beyond their rated CW safe operating region.