| Popis: |
The paper presents black-box type, behavioral model of pulse reflection from the open end of a transmission line. Model allows for setting measurements limits of TDR-based systems dedicated for DSL line diagnosis. Two main factors responsible for shape deterioration of the signal propagating through the line are ohmic conductor losses and frequency-dependent parasitic resistance induced mostly by a skin effect. Formal analysis of a problem is complicated, as it requires solving a set of differential equations. Behavioral model presented in this paper allows for easy estimation of amplitude and rise time of a reflected pulse using compact, analytical function of line length and testing pulse width. |
