Understanding pulsed IV measurement waveforms

Pulsed IV analysis allows the development of more accurate nonlinear models for RF and microwave device operation. An analysis of pulsed IV waveform allows better exploitation of measurement capabilities to produce accurate results. Static and dynamic IV measurement waveforms produced by a commercially available pulsed IV analyzer are examined. Because transistors can become unstable during any type of IV measurement, the use of bias tees allows a frequency-dependent impedance to be presented. However, it is shown that care must be used when using bias tees in pulsed IV measurement to choose a bias tee with an inductor time constant significantly higher than the pulsing frequency but lower than the frequency at which oscillations develop.