Effect of measurement bandwidth on time domain device modeling

The effect of the measurement system bandwidth on the time-domain modeling of microwave devices is investigated. The modeling is performed in the time domain using the modified transient circuit analysis package (MTCAP) together with TDR (time-domain reflectometry) waveforms experimentally measured for the device. Depending on the transition duration (rise time) of the TDR system, the details obtained on the TDR waveforms and consequently the complexity of the obtained model vary accordingly. It is shown that, with a faster TDR system, the modeling process is more difficult and the number of components in the equivalent circuit is increased. However, this equivalent network model gives a better characterization of the microwave device under test.<>