Preliminary Investigation of Impedance Discontinuity Detection on Wire Network Using Sequence Time Domain Reflectometry

We investigated impedance discontinuity detection on a wire network by applying sequence time domain reflectometry (STDR) using maximal-length sequence (M-sequence). We focused on impedance discontinuity detection under multiple reflection generated at nodes on a wire network. We first conducted a preliminary investigation of impedance discontinuity detection on a wire network with one node and confirmed that STDR resulting in cross-correlation of the observed signal with transmitted pulse train exhibits higher noise immunity than conventional TDR. We then demonstrated that STDR can distinguish the impedance discontinuity of various (resistive, inductive, and capacitive) impedance variations on a wire from the shape of the correlation response. Finally, we demonstrated that STDR can detect the location of impedance discontinuity due to small inductance and capacitance on a simple wire network with four nodes.