Lines with Reactive Terminations

Previous chapters have explored transmission lines terminated with resistive loads. In reality, most line terminations contain some reactance, such as the shunt capacitance arising from the pads of an integrated circuit. For example, Table 8.1 shows typical values of resistance and capacitance associated with several types of digital logic. The purpose of this lecture is to extend transmission line theory in order to incorporate the reactance into the analysis, and to study examples illustrating the resulting signal distortion. The presence of reactance generally provides an additional signal delay that must be accounted for in the design of digital systems, as well as an impedance mismatch that contributes to reflections, signal distortion, and “noise” in general.