A Noniterative Method for Locating Soft Faults in Complex Wire Networks

Reflectometry-based methods are the standard choice for fault-detection techniques in wire networks. While effective when dealing with simple networks and relatively hard faults, their results can be of more difficult interpretation if a network presents more than two branches. In this paper, we propose the use of an alternative technique based on a coherent multiport characterization of a network under test. The data thus collected are used to define excitation signals that will be focusing over the position of a fault, following a method already successfully applied in geophysical prospection techniques and nondestructive testing, namely, the DORT method, based on the synthesis of time-reversed signals. It is shown that a direct transposition of this technique to wire networks is not possible, due to the guided nature of wave propagation in wire networks, leading to the impossibility of assuming a dominant direction of propagation, as opposed to the case of propagation in open media. A differential version of the DORT method is introduced, enabling an accurate identification of the original position of faults. Numerical and experimental results are presented to demonstrate the feasibility of this approach.