Investigation on RF connector degradation using time domain reflectometry

Radio Frequency (RF) connectors play an important part in electronic and communication systems. They are generally subjected to degradation in the contact interface during their service life, which affects signal integrity and communication quality of the systems. In the present work, the characteristics of RF connector degradation were theoretically analyzed and experimentally investigated using Time Domain Reflectometry (TDR). An accelerated test was designed to obtain the degraded connector samples. A series of experiments were conducted to measure the reflected voltages using a Network Analyzer for time domain analysis. Then, the reflection coefficients and load impedance were determined and the location of the degraded contact interface was identified. Based on classical electrical contact theory, transmission lines theory, and experimental results, an equivalent circuit model was developed and the degradation mechanism analyzed. The results showed that inductive characteristics increase with increase of the degradation. As the degradation increases beyond a certain level, the connector exhibits a more capacitive characteristic.