Wiring fault detection with Boolean-chaos time-domain reflectometry

We experimentally demonstrate a time-domain reflectometry (TDR) method for detecting cable faults, which employs a Boolean circuit to generate a wideband chaotic waveform acting as probe signal and further locates faults by correlating a duplicate of the probe signal and the back-reflected signal. The Boolean circuit is a small delayed-feedback system mainly consisting of two exclusive-OR (XOR) gates and one exclusive-NOR gate. Benefiting from fast response and high operating voltage of logical gates, the Boolean circuit can achieve a high-bandwidth and large-amplitude output which cause a high resolution and a long measurable distance for the TDR. Our experimental results show that a 2km detection distance of a breakpoint and a similar to 0.1m spatial resolution can be achieved by means of a chaotic signal from the Boolean circuit with 533MHz bandwidth and 2.5V amplitude. Furthermore, we experimentally demonstrate the detection of short circuits and impedance mismatches can be successfully implemented using our method.