Time Domain Immittance Measurements

The fundamentals of the time domain reflectometry (TOR) are reinvestigated and the measuring method is extended to time domain transmission (TOT). It is shown, that for immittance measurements high resolution can be achieved by either decreasing the risetime or increasing the amplitude of the ramp test pulse. The effect of fixed reactances can often be neglected. It is easy to measure time constants of networks ¿ 0,1 ps. If the integral of the pulse response is taken into account. the measurements are independent of the pulse shape. For a quick evaluation of TDR- and TDT-oscillograms, groups of networks with equal network function can be listed in a normalized form. Results are shown for miniature components as well as microstrip parasitics.