Fault Location and Evaluation in Coaxial Cables Based on Stepped Frequency Waveform Reflectometry and Electromagnetic Time Reversal

Soft faults in coaxial cables, such as insulation aging and micro-cracks, can evolve into severe failures if not detected timely. Existing reflectometry-based techniques are capable of promising fault localization but lack the ability and accuracy in evaluating fault severity. In this study, we propose a method that combines Electromagnetic Time Reversal (EMTR) and Stepped-Frequency Waveform Reflectometry (SFWR) to enhance both fault location and evaluation. The proposed technique utilizes stepped-frequency signals for time reversal, enabling precise reconstruction of reflected waveforms in both time and frequency domains. A signal fitting and amplitude compensation algorithm is further applied to estimate reflection coefficients, allowing quantification of fault degree. Experimental validation on coaxial cables demonstrates that the method performs well both in fault location and reflection coefficient estimation. Moreover, the approach can simultaneously detect and assess multiple faults with an accuracy exceeding conventional methods. Compared to traditional SFWR and BIS, the proposed method significantly improves diagnostic accuracy and provides a more precise fault evaluation. The study also investigates the performance of the proposed method under noisy conditions, where the results demonstrate its favorable applicability, making it suitable for predictive maintenance in industrial cable networks.